Why is a swap file used?

Question

mint

There is a home computer with Linux Mint 18.1 Serena
There is 16 GB of RAM
There is 1 GB swap
Now used by 9% of programs, 90% as RAM cache
I know that this is normal and you should not worry, like when other programs need memory, the manager will free it from the buffer
But why -something got into swap and uses 200 MB, is this normal at all?

Answer 1

is this normal at all?

Yes