What is the difference between case-insensitive and sensitive?

Question

hello, so i started learning php and i am stuck here . what is the difference between case sensitive and insensitive?
thanks previously.

Answer 1

case sensitive : you must input the exact value, including uppercase and lowercase alphabet.. ex (hello, HeLLo) = false , (hello, hello) = true

insensitive : it doesn't mind wether its (hello, HeLLo) or ( Heyyy, HeYyY) wil always true as long as the alphabet is right..

Answer 2

The case of a font is the difference between uppercase and lowercase...

Sensitive: it feel the difference between both. (there's two different A -- 'a' := 'A')
Insentive: it don't feel/see the difference and consider lowercase equal to uppercase (it's a A, whatever it's 'a' or 'A' -- 'a' == 'A')