cool
Informal for very good, interesting, impressive, or fashionable.
Wow, dein neues Fahrrad ist echt cool!
Wow, your new bike is really cool!

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Informal for very good, interesting, impressive, or fashionable.
Wow, dein neues Fahrrad ist echt cool!
Wow, your new bike is really cool!

The word 'cool' comes from English and belongs to informal language. It is very common in everyday life, but should be avoided in formal texts or very formal conversations.
Dein Vortrag war echt cool, gut gemacht!
Your presentation was really cool, well done!
You can recognize the meaning of 'cool' from the context. If it refers to a thing or idea, it means 'toll' (great/cool) (m01). If it describes a person's behavior in a stressful situation, it means 'gelassen' (calm/composed) (m02).
Ein Auto, das von alleine parkt? Das ist ja cool!
A car that parks by itself? That's really cool!
In the meaning 'gelassen' (calm/composed), the phrase 'cool bleiben' (to stay cool) is very common. It is often used as advice or an instruction to remain calm.
Bleib cool, wir finden eine Lösung für das Problem.
Stay cool, we'll find a solution to the problem.
super
'super' and 'cool' can both express praise. With both, you say that you find something good, interesting, or impressive. 'super' is very general and fits almost any positive evaluation. 'cool' often sounds more youthful or casual and fits especially well when something seems interesting, modern, or impressive. In many everyday sentences, you can use both, but 'cool' has a bit more of a sense of style or impact.

Die neue App von Sofia ist richtig cool.
Sofia's new app is really cool.
Für die Familie ist der neue Esstisch super.
The new dining table is super for the family.