# What is the difference between [asymptotics], [big-o-notation], and [landau-notation]?

The tag currently has two tags remapped to it: and . I can imagine the reason is not amongst those is to distinguish between questions about asymptotics (in general) and the notation itself (and possibly its definition too); this seems to be what the tag description also hints at:

Questions about asymptotic notations such as Big-O, Omega, etc.

However, is there a good reason is not synonymous with (as in, e.g., Wikipedia)? Does merit its own tag? Its description currently reads:

Big O Notation is an informal name of the "O(x)" notation used to describe asymptotic behaviour of functions. It is a special case of .

So, is a special case of , which, in turn, is a special case of ? How are they related to the tag?