A time signature of 3/4 in music means count 3 quarter notes to each bar. This is an often-used time signature giving you a waltz feel.
The two numbers in the time signature tell you how many beats are in each measure of music. A piece with a time signature of 4/4 has four quarter note beats; each measure with a 3/4 meter has three quarter note beats; and each measure of 2/4 time has two quarter note beats.