Typ vs. Kerl
The German words Typ and Kerl both function as informal ways to say guy, dude, or man, but they carry slightly different nuances. While Typ is the most common and versatile word used to describe a man's general vibe, personality, or category, Kerl has a slightly more traditional, rustic, or emotional ring to it, often translating closer to fellow, chap, or lad.
Typ
The word Typ is a very common informal noun used to refer to a guy or dude, often focusing on his behavior, appearance, or the specific impression he gives off. It is also used exactly like the English word type to describe whether someone fits your romantic preferences or belongs to a certain category of people.
Er ist ein wirklich cooler Typ, mit dem man gerne Zeit verbringt.
(He is a really cool guy to spend time with.)
Was will dieser komische Typ da drüben von uns?
(What does this weird dude over there want from us?)
Ich kenne einen Typen, der dein Auto für wenig Geld reparieren kann.
(I know a guy who can fix your car for little money.)
Der neue Nachbar ist nett, aber er ist einfach nicht mein Typ.
(The new neighbor is nice, but he is simply not my type.)
Lass dich besser nicht mit solchen Typen ein.
(You better not get involved with those kinds of guys.)
Gestern hat mir ein fremder Typ auf der Straße einfach so eine Blume geschenkt.
(Yesterday a random guy on the street just gave me a flower for no reason.)
Kerl
The word Kerl translates to fellow, lad, or chap, and it often emphasizes a man's character, physical presence, or traditional masculinity. It is frequently used in established expressions to show sympathy for someone's misfortune or to praise a man for being reliable and sturdy.
Mein Großvater war ein richtig feiner Kerl, auf den man sich immer verlassen konnte.
(My grandfather was a really fine fellow whom you could always rely on.)
Der arme Kerl hat schon wieder seine Geldbörse im Zug vergessen.
(The poor fellow has forgotten his wallet on the train again.)
Man muss schon ein ganzer Kerl sein, um diese harte Arbeit zu machen.
(You have to be a real man to do this hard work.)
Unser neuer Hund ist ein zäher kleiner Kerl.
(Our new dog is a tough little fellow.)
Hast du gesehen, was für ein riesiger Kerl der Türsteher war?
(Did you see what a giant dude the bouncer was?)
Mit diesen fiesen Kerlen möchte ich nichts zu tun haben.
(I do not want anything to do with these nasty chaps.)
Summary
In short, use Typ when you are talking about an everyday guy, describing a man's general vibe, or expressing that someone is your romantic type. Use Kerl when you want to sound a bit more traditional, emphasize strong masculine character traits, or express emotional sympathy for a fellow.