The icon is a picture of two shirts. The shirts appear to be team jerseys with a number 3 on the first one. The icon is used to describe teams.
This Teams icon is made in Material Design style
developed by Google. This style is based on extremely simplified shapes, thin two-pixel lines, and is optimized for 24x24 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 5,700 icons, all in the same style and quality.