An obstacle is an object, thing, action or situation that causes an obstruction. There are, therefore, different types of obstacles, which can be physical, economic, biopsychosocial, cultural, political, technological or even military.

Physical barriers

As physical obstacles, we can enumerate all those physical barriers that block the action and prevent the progress or the achievement of a concrete goal. Examples:

• architectural
  Architecture
  Architecture is both the process and product of planning, designing and construction. Architectural works, in the material form of buildings, are often perceived as cultural and political symbols and as works of art...
  
   barriers that hinder access to people with reduced mobility;
• doors, gates, and access control
  Access control
  Access control refers to exerting control over who can interact with a resource. Often but not always, this involves an authority, who does the controlling. The resource can be a given building, group of buildings, or computer-based information system...
  
   systems, designed to keep intruders or attackers out;
• large objects, fallen trees or collapses through passageways, paths, roads, railroads, waterways or airfields, preventing mobility;
• sandbanks, rocks or coral reef
  Coral reef
  Coral reefs are underwater structures made from calcium carbonate secreted by corals. Coral reefs are colonies of tiny living animals found in marine waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps...
  
  s, preventing free navigation
  Navigation
  Navigation is the process of monitoring and controlling the movement of a craft or vehicle from one place to another. It is also the term of art used for the specialized knowledge used by navigators to perform navigation tasks...
  
  ;
• hills, mountains and weather phenomena preventing the free traffic of aircraft;
• meteor
  METEOR
  METEOR is a metric for the evaluation of machine translation output. The metric is based on the harmonic mean of unigram precision and recall, with recall weighted higher than precision...
  
  s, meteorite
  Meteorite
  A meteorite is a natural object originating in outer space that survives impact with the Earth's surface. Meteorites can be big or small. Most meteorites derive from small astronomical objects called meteoroids, but they are also sometimes produced by impacts of asteroids...
  
  s, micrometeorites, cosmic dust
  Cosmic dust
  Cosmic dust is a type of dust composed of particles in space which are a few molecules to 0.1 µm in size. Cosmic dust can be further distinguished by its astronomical location; for example: intergalactic dust, interstellar dust, interplanetary dust and circumplanetary dust .In our own Solar...
  
  , comet
  Comet
  A comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...
  
  s, space debris
  Space debris
  Space debris, also known as orbital debris, space junk, and space waste, is the collection of objects in orbit around Earth that were created by humans but no longer serve any useful purpose. These objects consist of everything from spent rocket stages and defunct satellites to erosion, explosion...
  
  , strong electromagnetic radiation
  Electromagnetic radiation
  Electromagnetic radiation is a form of energy that exhibits wave-like behavior as it travels through space...
  
   or gravitational field
  Gravitational field
  The gravitational field is a model used in physics to explain the existence of gravity. In its original concept, gravity was a force between point masses...
  
  , preventing a spacecraft
  Spacecraft
  A spacecraft or spaceship is a craft or machine designed for spaceflight. Spacecraft are used for a variety of purposes, including communications, earth observation, meteorology, navigation, planetary exploration and transportation of humans and cargo....
  
   from navigating freely in space.

Barriers in sports

In sports, a variety of physical barriers or obstacles were introduced in the competition rules to make them even more difficult and competitive:

• in the athletics, there are barriers in obstacle running contests of 110 meters and 3000 meters, as well as in high jump
  High jump
  The high jump is a track and field athletics event in which competitors must jump over a horizontal bar placed at measured heights without the aid of certain devices in its modern most practiced format; auxiliary weights and mounds have been used for assistance; rules have changed over the years....
  
   and in pole vault
  Pole vault
  Pole vaulting is a track and field event in which a person uses a long, flexible pole as an aid to leap over a bar. Pole jumping competitions were known to the ancient Greeks, as well as the Cretans and Celts...
  
  ;
• in equestrian
  Equestrianism
  Equestrianism more often known as riding, horseback riding or horse riding refers to the skill of riding, driving, or vaulting with horses...
  
   competitions, there are also jumps over obstacles
  Horse jumping obstacles
  Various obstacles are found in competitive sports involving Horse jumping. These include show jumping, hunter, and the cross-country phase of the equestrian discipline of eventing. The size and type of obstacles vary depending on the course and the level of the horse and rider, but all horses must...
  
  ;
• in tennis
  Tennis
  Tennis is a sport usually played between two players or between two teams of two players each . Each player uses a racket that is strung to strike a hollow rubber ball covered with felt over a net into the opponent's court. Tennis is an Olympic sport and is played at all levels of society at all...
  
   and volleyball
  Volleyball
  Volleyball is a team sport in which two teams of six players are separated by a net. Each team tries to score points by grounding a ball on the other team's court under organized rules.The complete rules are extensive...
  
  , a net stands as an obstacle that divides the court;
• in the cycling
  Cycling
  Cycling, also called bicycling or biking, is the use of bicycles for transport, recreation, or for sport. Persons engaged in cycling are cyclists or bicyclists...
  
  , motorcycle
  Motorcycle
  A motorcycle is a single-track, two-wheeled motor vehicle. Motorcycles vary considerably depending on the task for which they are designed, such as long distance travel, navigating congested urban traffic, cruising, sport and racing, or off-road conditions.Motorcycles are one of the most...
  
   and motor racing, circuit designs are interposed with difficult paths to obstruct and render more difficult the competition;
• in team sports, like soccer, football
  Football
  Football may refer to one of a number of team sports which all involve, to varying degrees, kicking a ball with the foot to score a goal. The most popular of these sports worldwide is association football, more commonly known as just "football" or "soccer"...
  
  , basketball
  Basketball
  Basketball is a team sport in which two teams of five players try to score points by throwing or "shooting" a ball through the top of a basketball hoop while following a set of rules...
  
   and volleyball, attack players are hampered by defensive players, that make it difficult to move or throw the ball towards the goal;
• in other sports, such as Parkour
  Parkour
  Parkour is a method of movement focused on moving around obstacles with speed and efficiency. Originally developed in France, the main purpose of the discipline is to teach participants how to move through their environment by vaulting, rolling, running, climbing and jumping...
  
  , the competitor aims to move from one point to another in the most fluid and fast as possible, jumping obstacles of urban architecture that get in the way.

Economic barriers

Can be defined as those elements of material deprivation that people may have to achieve certain goals, such as:

• the lack of money as an obstacle to the development of certain projects;
• the lack of water as an obstacle to human capacity to produce certain crops on the field and to their own survival;
• the lack of light as an obstacle to mobility at night;
• the lack of electricity
  Electricity
  Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...
  
   as an obstacle to the benefits provided by electronic devices and electrical machines;
• the lack of schools and teachers as obstacles to education and the fullness of citizenship;
• the lack of hospitals and physician
  Physician
  A physician is a health care provider who practices the profession of medicine, which is concerned with promoting, maintaining or restoring human health through the study, diagnosis, and treatment of disease, injury and other physical and mental impairments...
  
  s as obstacles to a system for the improvement of public health
  Public health
  Public health is "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals" . It is concerned with threats to health based on population health...
  
  ;
• the lack of transportation infrastructure
  Infrastructure
  Infrastructure is basic physical and organizational structures needed for the operation of a society or enterprise, or the services and facilities necessary for an economy to function...
  
   as an obstacle to trade, industrial and tourism activities, among others, and to economic development
  Economic development
  Economic development generally refers to the sustained, concerted actions of policymakers and communities that promote the standard of living and economic health of a specific area...
  
  .

Biopsychosocial and cultural barriers

People are prevented to achieve certain goals by biological, psychological, social or cultural barriers, such as:

• diseases, as obstacles to human life in its fullness;
• physical disabilities as obstacles to the mobility of handicapped
  Handicapped
  Handicapped or handicap may refer to:*Handicapping, various methods of leveling a sport or game**Golf handicap, a sport-specific handicapping method**Go handicaps**Handicaps in shogi**Asian handicap, bookmakers technique to level odds...
  
  , which can be facilitated by accessibility
  Accessibility
  Accessibility is a general term used to describe the degree to which a product, device, service, or environment is available to as many people as possible. Accessibility can be viewed as the "ability to access" and benefit from some system or entity...
  
   resources;
• shyness as an obstacle to social relations;
• fear as an obstacle that prevents facing potential enemies or socio-political opponents, or facing possible economic barriers;
• social exclusion
  Social exclusion
  Social exclusion is a concept used in many parts of the world to characterise contemporary forms of social disadvantage. Dr. Lynn Todman, director of the Institute on Social Exclusion at the Adler School of Professional Psychology, suggests that social exclusion refers to processes in which...
  
   or the arrest of individuals as obstacles to socio-cultural integration into a community;
• the lack of psychomotor coordination
  Motor coordination
  thumb|right|Motor coordination is shown in this animated sequence by [[Eadweard Muybridge]] of himself throwing a diskMotor coordination is the combination of body movements created with the kinematic and kinetic parameters that result in intended actions. Such movements usually smoothly and...
  
   as an obstacle to the development of qualified abilities
  Skill
  A skill is the learned capacity to carry out pre-determined results often with the minimum outlay of time, energy, or both. Skills can often be divided into domain-general and domain-specific skills...
  
  ;
• the level of mastery of the spoken idiom
  Idiom
  Idiom is an expression, word, or phrase that has a figurative meaning that is comprehended in regard to a common use of that expression that is separate from the literal meaning or definition of the words of which it is made...
  
  , or the differences between the spoken languages, as barriers to national or international social relations;
• the different religions as obstacles to the mutual moral
  Moral
  A moral is a message conveyed or a lesson to be learned from a story or event. The moral may be left to the hearer, reader or viewer to determine for themselves, or may be explicitly encapsulated in a maxim...
  
   understanding or interreligious dialogue
  Interfaith
  The term interfaith dialogue refers to cooperative, constructive and positive interaction between people of different religious traditions and/or spiritual or humanistic beliefs, at both the individual and institutional levels...
  
  , nationally or internationally;

Political barriers

Obstacles or difficulties which groups of citizens, their political representatives

Representation (politics)

In politics, representation describes how some individuals stand in for others or a group of others, for a certain time period. Representation usually refers to representative democracies, where elected officials nominally speak for their constituents in the legislature...

, political parties

Political party

A political party is a political organization that typically seeks to influence government policy, usually by nominating their own candidates and trying to seat them in political office. Parties participate in electoral campaigns, educational outreach or protest actions...

 or countries interpose to each other in order to hinder the actions of certain of their opponents, such as:

• the prevention of a political minority group
  Minority group
  A minority is a sociological group within a demographic. The demographic could be based on many factors from ethnicity, gender, wealth, power, etc. The term extends to numerous situations, and civilizations within history, despite the misnomer of minorities associated with a numerical statistic...
  
   to achieving their aspirations in the parliament
  Parliament
  A parliament is a legislature, especially in those countries whose system of government is based on the Westminster system modeled after that of the United Kingdom. The name is derived from the French , the action of parler : a parlement is a discussion. The term came to mean a meeting at which...
  
   by the politically dominant voting majority
  Majority
  A majority is a subset of a group consisting of more than half of its members. This can be compared to a plurality, which is a subset larger than any other subset; i.e. a plurality is not necessarily a majority as the largest subset may consist of less than half the group's population...
  
  , in the legislative procedure;
• the ideological repression
  Ideological repression
  Ideological repression refers to forceful activities against competing ideologies and philosophies.Alan Wolfe defines ideological repression as "the attempt to manipulate people's consciousness so they accept the ruling ideology, and distrust and refuse to be moved by competing ideologies".Among...
  
  , persecution and imprisonment for political reasons
  Political prisoner
  According to the Longman Dictionary of Contemporary English, a political prisoner is ‘someone who is in prison because they have opposed or criticized the government of their own country’....
  
  ;
• the blocking of the international political and economic influence
  Sphere of influence
  In the field of international relations, a sphere of influence is a spatial region or conceptual division over which a state or organization has significant cultural, economic, military or political influence....
  
   of a country by a multilateral treaty
  Multilateral treaty
  A multilateral treaty is a treaty to which three or more sovereign states are parties. Each party owes the same obligations to all other parties, except to the extent that they have stated reservations...
  
   or alliance between countries opposed to such influence.

Technological barriers

The improvement of living conditions of any human community is constantly challenged by the need of technologies still inaccessible or unavailable, which can be internally developed or acquired from other communities that have already developed them, and in both cases must overcome such barriers as:

• in the technology transfer
  Technology transfer
  Technology Transfer, also called Transfer of Technology and Technology Commercialisation, is the process of skill transferring, knowledge, technologies, methods of manufacturing, samples of manufacturing and facilities among governments or universities and other institutions to ensure that...
  
   between different countries, the trade and diplomatic negotiating skills with the countries which are providers of the desired new technologies;
• in the internal development approach, the educational level of the community or country, the accessible collection of specialized information, their technological and industrial base, their institutional level of scientific and technological research, development and innovation, and the level of practiced international collaboration.

Military barriers

When different communities or countries, which border or not, can not develop good relations, for economic, cultural or political reasons, they may exceed the limits of diplomatic negotiations, creating military defensive or offensive obstacles to their opponents or enemies, such as:

• blocking or destroying physical resources or logistic
  Logistics
  Logistics is the management of the flow of goods between the point of origin and the point of destination in order to meet the requirements of customers or corporations. Logistics involves the integration of information, transportation, inventory, warehousing, material handling, and packaging, and...
  
   interconnections, such as bridges, highways, ports or airports, creating barriers to migration
  Human migration
  Human migration is physical movement by humans from one area to another, sometimes over long distances or in large groups. Historically this movement was nomadic, often causing significant conflict with the indigenous population and their displacement or cultural assimilation. Only a few nomadic...
  
  , trade, tourism, etc.;
• the invasion of the opponent's territory, seeking to block, destroy or use physical, logistical or strategic resources, in order to hinder existing threats.