It seems you are describing music notation.
A whole note, represented as a hollow oval, is a note that lasts for four beats in a 4/4 time signature.
A half note, shown as a hollow oval with a stem, lasts for two beats.
A quarter note, which would be filled in (usually a black oval with a stem), lasts for one beat.
A quarter rest is a symbol for a silence that lasts for one beat.
If you have a specific question or need further clarification on music notation, feel free to ask!