Peter Parker's second Stark-made Spidey suit is the Iron Spider armor, a significant upgrade that closes the gap between friendly neighborhood Spider-Man and Avenger. Since there was seemingly no physical Iron Spider costume on set (behind-the-scenes photos show Tom Holland in a motion capture suit while the Iron Spider armor is in action), it was pretty much the sole creation of Ryan Meinerding, loosely inspired by the Iron Spider armor in the comics as designed by Joe Quesada.
For Holland's Peter, the Iron Spider armor represents everything he thought he wanted at the beginning of "Spider-Man: Homecoming" — that Avengers-level worthiness coupled with the capability to fight bigger, badder threats. When he dons it in "Avengers: Infinity War," however, it's given to him not because he's finally ready but out of necessity — given that he's falling from the sky — emphasizing how the responsibility to fight the universal threat that is Thanos (Josh Brolin) is thrust upon him.
In "Spider-Man: Far from Home," the Iron Spider armor has replaced Peter's primary Stark suit, perhaps symbolizing that Peter feels he can't be a friendly neighborhood Spider-Man anymore, much less a normal kid. Coupled with his grief over Tony's death, the Iron Spider armor comes to represent the dream he achieved and the price he paid for it.
