What are the two numbers at the beginning of a staff in music called?

Some one please answer it!

Those two numbers are the "time signature." The top number indicates how many beats are in a measure, and the bottom number indicates what note equals one beat. For example, in 3/4 time there are three beats per measure and a quarter note equals one beat. In 6/8 time, there are six beats per measure and an eighth note is one beat.