Epistemology i/ɨˌpɪstɨˈmɒlədʒi/ (from Greek ἐπιστήμη (epistēmē), meaning "knowledge, understanding", and λόγος (logos), meaning "study of") is the branch of philosophy concerned with the nature and scope (limitations) of knowledge.
It addresses mainly the following questions:

  • What is knowledge?
  • How is knowledge acquired?
  • To what extent is it possible for a given subject or entity to be known?

Much of the debate in this field has focused on analyzing the nature of knowledge and how it relates to connected notions such as truth, belief, and justification. One view is the objection that there is very little or no knowledge at all—skepticism. The field is sometimes referred to as the theory of knowledge.

The term was introduced by the Scottish philosopher James Frederick Ferrier (1808–1864).

Read more about Epistemology:  Knowledge, Acquiring Knowledge, What Do People Know?, Practical Applications