2-group

The term 2-group may refer to either of the following:

• Most typical usage in group theory: p-group for the prime $p=2$. This means that the order of every element is a power of 2. For more on the finite 2-groups, see groups of order 2^n. For background on finite p-groups, see group of prime power order.
• Usage in higher category theory: See strict 2-group and 2-group (categorical sense)