I already posted this pic as example of various 24 mm (slightly below 1") Stahlwille sockets, 3/8" , 1/2" and 3/4" non-impact and 1/2", 3/4" and 1" impact.
According to ISO standards the hardness range for impact (i.e. machine-driven) sockets is higher than the one for non-impact (i.e. hand-driven). Also as already mentioned by others, the wall thickness is different.
For low torque peaks, typically to unscrew already loosened parst it's not a problem to use non-impact sockets though they can fall off the driving square if there's no retaining clip as those sockets don't feature radial holes.
Applying regular impact torques can damage non-impact sockets and even presents an inury risk due to expelled debris when a socket fails catastrophically (never saw it myself though).
Overall it's a matter of common sense, the problem being that a regular socket can end damaged, also its female square can be damaged more easily due to its lower hardness.