A novice user reading Q/A here: I sometime need to just understand the syntax and meaning of commands exampled here. where is the best place to find it?
Built-in Mathematica symbols can be looked up directly in a Mathematica session by selecting the symbol/command text and hitting F1. This is also available in the menu: Help --> Find Selected Function.
The online Wolfram language reference includes categories for digging through the documentation, but it also includes a search box which can be used to quickly lookup symbols, built-in functions, packages, and related topics: