Are squibs real in Harry Potter?

[Allie Preissler]

Well my friend told me a while back that mr. Filch and mrs. Figg were "squibs", but what in fact is a squib, and are they a factual thing? 

[kıvılcım açıkgöz]

a squib is a non-magical person born in a magical family. they're simply muggles but the fact that they come from a witch and a wizard is unexpected.

if that was what you were asking...

[Kayla Leigh Grover]

A squib is sort of the reverse of a muggle-born wizard. They're a muggle born into a magical family. 

[Peter Nolan-Smith]

A squib is a small, tailless cat, native only to the Isle of Man.

[Emily Wallace]

To answer your question, yes- they are an actual thing. As others have said, they're a person born into a wizarding family who doesn't posses magical powers.