Notes values tell you how long a note "rings out", or lasts. It could be a sudden note that cuts off, or a looong held note. Musical notation comes with "standardized" note values, which you can piece together to write out your desired note duration.
This is called a whole note it is equal to 4 beats.
This is called a half note, it is equal to 2 beats.
This is called a quarter note, it is equal to 1 beat.
This is called a eighth note, it is equal to half a beat or two evenly placed notes every beat.
This is called a sixteenth note, it is equal to a quarter of a beat or four evenly placed notes every beat.
This is called a thirty second note, it is equal to an or eight evenly placed notes every beat.
Matter is to antimatter, as "notes" are to "rests".
While notes mark times when sounds are played, rests mark times when no sounds are played.
Just as notes are drawn differently, depending on their time values, rests are drawn differently also, depending on their time values.
You can see in the figure below how rests are notated.
Have you ever seen those Matryoshka Dolls? (Those Russian "doll in doll in doll in doll" toys.)
In the same way, notes with short time values can mathematically fit "inside" notes with longer time values.
Here are some examples of how note values can fit "inside" one another:
This figure below gives visual representation this: