eli5: why do most, if not all, breathing techniques specify ‘out through the mouth’?

Question

i can understand in ‘through the nose’, since dust and other bits can be blocked by the nose hairs and mucus, and apparently the air is more likely to warm up when passing through the nose first, reducing irritation of the throat.

but what difference, if any, does exhaling through the mouth make?

In: 676

Answer 1

So, I usually breath in and out through my nose. Should I make a habit of exhaling through the mouth?