The lower number is the note duration that should be considered a beat. E.g. 2/4 time means that a quarter note is a beat, and there are two of them in each measure. 6/8 time means that there are 6 eighth notes in each measure.
two
The top note of the time signature tells you how many beats are in a bar; so, in this case four. The bottom number would tell you what kind of note gets one beat.
The number of beats in the bar.
quarter note
Time Signature
The top number of a time signature tells you how many beats are in each measure of music.
two
The top number in a time signature tells you how many beats are in each measure of music.
The top number of a time signature tells you how many beats are in each measure of music.
The top number in a time signature tells you how many beats are in each measure of a musical piece.
The top number of a time signature tells us how many beats are in each measure of music.
The top number of a time signature tells us how many beats are in each measure of music.
The bottom number indicates what duration of note gets the beat.
The top number indicates the number of beats per measure.
The bottom number indicates what note value gets one beat.
The top number in a time signature tells us how many beats are in each measure of a musical piece.
It means there are two notes to the bar, of the size indicated by the lower number.