"Source" means data that originates from either primary of secondary source. An information source is a source of information

Information

Information in its most restricted technical sense is a message or collection of messages that consists of an ordered sequence of symbols, or it is the meaning that can be interpreted from such a message or collection of messages. Information can be recorded or transmitted. It can be recorded as...

 for somebody, i.e. anything that might inform a person about something or provide knowledge to somebody. Information sources may be observations, people, speeches, documents, pictures, organizations etc. They may be primary source

Primary source

Primary source is a term used in a number of disciplines to describe source material that is closest to the person, information, period, or idea being studied....

s, secondary source

Secondary source

In scholarship, a secondary source is a document or recording that relates or discusses information originally presented elsewhere. A secondary source contrasts with a primary source, which is an original source of the information being discussed; a primary source can be a person with direct...

s, tertiary source

Tertiary source

In scholarship, a tertiary source is a term used to describe a work which is chiefly a selection or compilation of other primary and secondary sources. The distinction between a secondary and tertiary source is relative, whereas the difference between primary and secondary sources is more absolute...

s and so on.

Empiricism

Empiricism

Empiricism is a theory of knowledge that asserts that knowledge comes only or primarily via sensory experience. One of several views of epistemology, the study of human knowledge, along with rationalism, idealism and historicism, empiricism emphasizes the role of experience and evidence,...

 regards sense data as the ultimate information sources, while other epistemologies have different views (cf., source criticism

Source criticism

A source criticism is a published source evaluation . An information source may be a document, a person, a speech, a fingerprint, a photo, an observation or anything used in order to obtain knowledge. In relation to a given purpose, a given information source may be more or less valid, reliable or...

).