Baseline

The term baseline can have several meanings depending on the context. It may refer to:

Baseline (compatibility)
Baseline identifies the availability of web platform features across popular browsers, including APIs, CSS properties, and JavaScript syntax. Baseline describes web features as being either widely available or newly available. Features that do not meet the Baseline criteria are said to have limited availability.
Baseline (typography)
The baseline is a term used in European and West Asian typography meaning an imaginary line upon which the most characters of a font rest.