A first aid kit is a collection of supplies and equipment for use in giving first aid

First aid

First aid is the provision of initial care for an illness or injury. It is usually performed by non-expert, but trained personnel to a sick or injured person until definitive medical treatment can be accessed. Certain self-limiting illnesses or minor injuries may not require further medical care...

, and can put together for the purpose (by an individual or organization, for instance), or purchased complete. There is a wide variation in the contents of first aid kits based on the knowledge and experience of those putting it together, the differing first aid requirements of the area where it may be used, and variations in legislation or regulation in a given area.

The international standard for first aid kits is that they should be identified with the ISO graphical symbol for first aid (from ISO 7010) which is an equal white cross on a green background, although many kits do not comply with this standard, either because they are put together by an individual or they predate the standards.
First aid kits can be assembled in almost any type of container, and this will depend on whether they are commercially produced or assembled by an individual.