U could use also an another apology from 2 glasses with water:

When u swap several times ( and also vice) versa certain amount of liquid from one to the other without loss any liquid. This is ur channel.

If u close the channel, then u swap ur glass of water in an bottle.

And u loose some liquid in this process ( that's the on chain transaction for ur sats to an Bitcoin Adress (the bottle).

And forced close is like the same as above but u get ur bottle of water later for several reasons, like one glass was destroyed. that's for ex. channel partner isn't reachable or an bug on their lightning node etc.