An inning is one of the main sections of a baseball or softball game, like a chapter in a book or a quarter in basketball. During each inning, both teams get a turn to bat and try to score runs while the other team plays defense in the field.

A regulation baseball game has nine innings (softball usually has seven). Each inning has two halves: the visiting team bats first in the top of the inning, and the home team bats in the bottom of the inning. A team's turn at bat continues until the fielding team gets three outs, then the teams switch roles.

When someone says a baseball game went into extra innings, it means the score was tied after nine innings, so they kept playing additional innings until one team was ahead at the end of an inning. If you hear that a pitcher “pitched six strong innings,” it means they played well for six of the game's nine sections before another pitcher took over.