This is the generation that produces the offspring.

F1 or first filial generation produces the offspring.

Explanation:

The generation coming from the parental generation is referred as F1 generation.

When the male and female parent interbreed they produced F1 generation.

In F1 generation if homozygous dominant and recessive dominant are crossed only heterozygous dominant are produced although the recessive trait is present,

The F1 generation tells about the dominant and recessive genes present and their occurrence in subsequent F2 generation or so.