Imagine you're moving to a new house. You've got a whole pile of stuff to pack, so you grab some cardboard boxes. You put your books in one box and write BOOKS on the side with a marker. You put your shoes in another and label it SHOES. Your collection of 47 slightly different phone chargers goes in a box labeled CABLES (WHY SO MANY?).
Later, when you want your books, you don't need to open every box. You just look for the one labeled BOOKS.
That's exactly what a variable is.
A variable is a named box that holds a value. You give the box a name (the label), put something inside it (the value), and whenever you need that value later, you just ask for it by name.
Programs need variables because computers don't remember anything unless you tell them to. Without variables, your program would be like a goldfish: every line of code would forget everything that happened in the line before. With variables, your program can remember a user's name, keep track of a score in a game, store the price of a pair of shoes, and much more.