Expanding on Rock2000''s post...

Each digit in hex corresponds exactly to 4 bits in a binary sequence. i.e.
8 hex corresponds to 0100 binary.
F hex corresponds to 1111 binary
therefore
8F hex corresponds to 01001111 binary.

In decimal, there is no direct correspondance like that. Hex is useful for compressing long binary sequences.
I would rather read F801h than 1111010000000001b.

Mike