What exactly constitutes "Squibdom"?

[sawsan_issa]

No: HPFGUIDX 88546

Carol wrote:
<Granted, he sold a wand to "little" Hagrid, but Hagrid must have
come to the shop accompanied by his wizard father and must have been
listed in the book that records the birth of magical children or he
wouldn't have received a letter from Hogwarts.>

Sawsan here:
Hagrid does have powers, but after the Chamber of Secrets problem
during his school year I think they might have stopped him from using
them. In the Sorceror's stone he uses his umbrella to light a fire and
he grew a pig tail on Dudley. So he must be a wizard. He just probably
isn't allowed to use it that much considering his record. He did ask
Harry not to mention it to anyone. Filch, who is a squib can't do any
sort of Magic at all apparently, and neither can Mrs. Figg, who is
another squib. As for squibs and magic, I think that, just as
severelysigune wrote, they are the exact opposites of muggleborn wizards.