This is a half note (or minim). It lasts for two counts or two beats. There are two half notes in one bar of * time.
One half note takes the same amount of time as two quarter notes.
This song contains four bars of half notes. Play where you see big counting numbers and count but don't play on the small counting numbers. Because the song is in * time it is important to keep counting 1, 2, 3, 4, 1, 2, 3, 4 throughout each bar.
This is a whole note (or semibreve).
It lasts for four beats. There is one whole note in one bar of * time.
One whole note takes the same amount of time as two half notes or four quarter notes.
When you play a whole note on the first beat of a bar, it means you won't play another note until the following bar. However, it is important to keep counting even when you are not playing a note.
You have now learned three different kinds of notes - the whole note, the half note and the quarter note. A whole note has equal time to two half notes and a half note has equal time to two quarter notes, while four quarter notes make up a whole note. All these things are shown in the table here.
In music it is common to use both quarter notes and half notes in the same bar. Count the beats in the following song and see that every bar adds up to four beats. Write the beats under the staff if you need to.