What is the difference between a quarter note and an eighth note? How are the notes sung/counted differently

When a quarter note is assigned the time value of 1, an eighth note will receive a time value of one-half. When two eighth notes are grouped together it is easy to divide the "1" in half and think "one and"in rhythm for the two notes

they are often in theme and variations

so, not gonna do the actual thing because that's just laziness for an easy assignment like this.

but someone that has a lot of information and interesting details about is picasso. you can easily write a 500 word essay about him and how overtime his paintings of himself got more and more deformed representing that he was forgetting what he looked like and that was from memory.