Why do computers need RAM memory? And why some programs require lots of it while others require less?

Question

Just curious about it, but can’t understand why is it like that.

In: 7

Answer 1

Think of a kitchen:

The fridge is the hard drive, it stores things for the long term.
The kitchen counter is memory.
The cook is the CPU.

Can the cook make a meal directly in the fridge? No, the fridge is made for holding lots of ingredients, not for chopping and mixing.

The cook needs the kitchen counter to cook the ingredients from the fridge. It first gets the ingredients from the fridge (hard drive), works with it on the counter (memory), and delivers the meal/result (output).