Even though both Peter Parker and Miles Morales are both technically "Spider-Man," there are a number of differences in their power sets that make their overall fighting styles somewhat different. In the newest trailer for Sony's Spider-Man: Into the Spider-Verse, the pair come to realise that there's a lot they don't know about one another.
In Marvel's comics, the radioactive spider that imbues Miles with his powers is just different enough that, in addition to all of the classic Spidey abilities, the teen also learns that he's able to shoot energy blasts that mess with people's bioelectricity and he's also capable of rendering himself invisible.
The new Spider-Verse trailer shows Peter marvelling at Miles' newfound stealth powers and Miles, for his part, is too scared with the task at hand to really be concerned with the fact that being afraid makes him impossible to see.
It's little moments like that that make the idea of seeing a whole squad of Spider-People teaming up so exciting.