why do people say that we boil at different degrees ?

Answer 1

In terms of science, water boils at different temperatures depending on the pressure.

Near sea level water boils at 100 Celsius (252F, 373K)
But the further you go up in the atmosphere the pressure lowers.
At lower pressures water boils at lower temperatures.
For example water boils at roughly 69 Celsius.

(Of course, water with impurities also boils at different temperatures, but that is another whole answer)
What a difference, imagine at 69 Celsius your coffee would only be warm, not very hot!

Answer 2

The boiling of water will be 212 deg.F. at sea level.