What does sending weapons mean in terms of money changing hands between countries?

For months I'm hearing from multinational sources of sending weapons to Ukraine. They are all vague or deceptive on what the term "sending" means.

1. Does it mean selling weapons for high profit?
2. Does it mean selling weapons with no profit in mind or even make the price laughably cheap (but you still could call this a sale)?
3. Does it mean giving weapons out for free?

I'm especially interested about US and German weapons.