What is fire resistance?

Answer 1

Resistance means barrier to something. And I hope you know what is fire?

ans2. Fire Resistance Rating is a formal measurement of fire rating. It is used to provide a relative rating for fire resistance for doors, walls, etc.
The rating is measured in a standard test rig, and with a 'standardized fire'. These are laid out in various standards.
Ratings are commonly given in 30 minute increments, as anything between these intervals is unimportant in the context.
Some rating numbers however refer to the temperature profile against time, of the fire.

Answer 2

When something is resistant to fire it burns slower.

Answer 3

it doesnt catch fire