There have been many variations of Spider-Man from many alternative universes. This was fully shown in SMG4: If Mario Was Spiderman where multiple spider-people from the spider-vere were brought to the SMG4 universe to face villains.
Spider-Man is the main spider-man of the SMG4 universe despite having other appearance earlier in the series. This iteration has the design of Tom Holland's iteration of the character from the Marvel Cinematic Universe and met a tragic fate in SMG4: If Mario Was Spiderman where he has a major role despite dying at the beginning.
Spider-Man made his first appearance in SMG4: The Minecraft Plague where he was one of the many citizens turned into a Minecraft mob him being a spider and when turned back stated that with great power comes great big butts. He would later have many other appearances like in SMG4: She's Back!.
Miles Morales is one of the many spider-men from the Spider-verse that were summoned by the the Green Goober in order to fight villains from different universes.
Spider-Gwen is a Spider-woman (Sometimes referred to as "Ghost-Spider" in some media) from the Spider-verse who was summoned by the Green Goober in order to stop villains that escaped their reality and entered the SMG4 universe.
Spider-Man (Alternate Peter Parker)
The suit of this Spider-Man has appeared on the SMG4 universe's Spider-Man a few times though mostly as a toy with his first physical appearance in it being in SMG4: Little Penguin Lost. However this Spider-Man's major appearance was when he was summoned by Luigi/Green Goober as one of the many Spider-People to help defeat the villains that came to the SMG4 universe.
This Spider-Man is the Pyro from TF2 but recolored to look like Spider-Man. He appeared in SMG4: If Mario Was Spiderman and is the spider-man that defeat Kingpin due to the fact that he is invulnerable to fire.
Spider-Man 2099 also known as Miguel O' Hara has appeared in more than one SMG4 video in the SMG4 Universe over the years the first one being a minor appearance as a ragdoll toy alongside Spider-Punk in SMG4: The Mario Convention!. Then he had a more major yet still minor appearance in SMG4: If Mario Was Spiderman where he helped Mario and Luigi stop the villains that came to the SMG4 universe.
The Black Tarantula is a Spider-Man villain from Marvel Comics who has longevity and super strength. In SMG4: If Mario Was Spiderman he appears as one of the many spider-men that came to save the SMG4 universe from villains. His addition is most likely a mistake as he doesn't have spider powers but do have a spider symbol on his face.
Spinneret also known as Mary Jane Watson-Parker is in the comics an alternate universe version of Spider-Man's wife Mary Jane Watson gaining powers from her suit. She appeared along with other Spider-People in the episode SMG4: If Mario Was Spiderman.
Spider-woman (real name Jessica Drew) is one of the many Spider-People from the Spider-verse, she is a female clone of Peter Parker. In SMG4: If Mario Was Spiderman she appeared along with other Spider-People to save the SMG4 universe from villains.