To put it simply: Postman is for everything but what curl is for. Sure it also performs the actual request somewhere under the hood but that’s mostly irrelevant. Having a single integrated user interface (it could also be a text UI) to craft a request, sometimes sending JSON, sometimes a file, then sending it to inspect the result, then modifying the request then doing it again is very powerful. Not to mention OAuth/OIDC support and the like.
Sometimes, you have to find out how an API works, exactly. Sometimes you want to test your own APIs in ways the regular clients do not allow.
Sometimes, you have to find out how an API works, exactly. Sometimes you want to test your own APIs in ways the regular clients do not allow.