When you swapped something, you gave something to someone and they gave you something else in return.
Swapping can be a fun way to get something new without spending money.
Examples:
I swapped my toy for a candy.
We swapped our sandwiches at lunch.
She swapped her book for a different one.
I swapped my apple for his orange, but then I wished I had kept my apple!
We swapped our bikes for skateboards, and it was so much fun!
He swapped his hat for a bigger one, and it was funny to see.