The pursuit of lexicography is divided into two related disciplines:

• Practical lexicography is the art or craft of compiling, writing and editing dictionaries.
• Theoretical lexicography is the scholary discipline of analyzing and describing the semantic relationships within the lexicon (vocabulary) of a language and developing theories of dictionary components and structures linking the data in dictionaries. This is sometimes referred to as metalexicography.

A person devoted to lexicography is called a lexicographer, famously defined in Samuel Johnson's Dictionary of the English Language (1755) as "A writer of dictionaries; a harmless drudge that busies himself in tracing the original, and detailing the signification of words".

General lexicography focuses on the design, compilation, use and evaluation of general dictionaries, i.e. dictionaries that provide a description of the language in general use. Such a dictionary is usually called a general dictionary or LGP dictionary. Specialized lexicography focuses on the design, compilation, use and evaluation of specialized dictionaries, i.e. dictionaries that are devoted to a (relatively restricted) set of linguistic and factual elements of one or more specialist subject fields, e.g. legal lexicography. Such a dictionary is usually called a specialized dictionary or LSP dictionary.

There is some disagreement on the definition of lexicology, as distinct from lexicography. Some use "lexicology" as a synonym for theoretical lexicography; others use it to mean a branch of linguistics pertaining to the inventory of words in a particular language.

It is now widely accepted that lexicography is a scholarly discipline in its own right and not a sub-branch of linguistics.