This is a half note strum.
It lasts for two beats.
There are two half note strums in one bar of * time.
This is a quarter note strum.
It lasts for one beat.
There are four quarter note strums in one bar of * time.
These are a pair of eighth note strums.
Each strum lasts for half a beat.
There are eight eighth note strums in one bar of * time.
Play the larger downward strum louder.
These Strums are a group of sixteenth note strums.
Each strum lasts for one quarter of a beat.
There are sixteen sixteenth note strums in one bar of * time.
Play the larger downward strum louder.
This is a group of three eighth note triplet strums.
Each strum in the group lasts for one third of a beat.
There are twelve eighth note triplet strums in one bar of * time.
Play the larger downward strum louder.
A broken strum symbol indicates that the strings are not to be strummed.