How are swallows and swifts similar and different?

Similarities:
1) The proportions of the body, shape of the head and wings are very similar.
2) Both the swift and the swallow fly south in winter.
3) They catch insects in the air, they can drink on the fly.
4) Both birds have a forked tail.

Despite the above similarities, there are quite a few things that distinguish them:
1) Swifts belong to the order of swift-like, and swallows belong to the order of passerines.
2) It is very easy to distinguish them if you observe their flight –
swallows periodically fold their wings when they fly, but swifts never do that.
3) Swifts scream when they fly.
4) The swift has a black belly (a white speck can be seen), while the swallow has it white.
5) Another weight difference is their “habitat” – so swifts can often be found in urban areas, and swallows – in rural areas.