# Set theory

## branch of mathematics that studies sets, which are collections of objects / From Wikipedia, the free encyclopedia

**Set theory** is the study of sets in mathematics. Sets are collections of objects. We refer to these objects as "elements" or "members" of the set. To write a set, one wraps the numbers in {curly brackets}, and separates them with commas. For example. the set $\{1,2,3\}$ holds 1, 2, and 3. Sets are also often referred to using capital roman letters such as $A$, $B$, $C$.^{[1]}

There are three methods one can use to describe a set: Description method, Roster method (tabular form) and Rule method (set builder form).