What do you mean by case sensitive?

Answer 1

Krishana_Vanve and krishava_vanve is not the same.

lower or uppercase makes the variable different.

Example:

Krishava = 1
krishava = krishava + 1
print(krishava)

Output will be error.
It will say 'Not defined krishava'.

some example;
integer - int

int a;

Int a; // here it will be error
as Int is not same as int.

Usernames

File names

Tags

Commands

Variable names

Text string searches within electronic text can usually be sensitive to case or not, as required

Passwords are almost always case-sensitive.

the password SoloLearN#1$ is only valid if it's entered in that exact way.

If user enter sololearn#1$ or any other way then it will be not valid.

URLs 

Those above are usually case-insensitive.

int a = 0;

A = 23
print(A)

Here, we let a = 0
and then we name variable to uppercase 'A' which is because of case sensitive there will be error.

To fix :
int a = 0; or int A= 0;

a = 23; or A = 23;
print(a); or print(A)

Answer 2

Cares about whether the characters in a string are uppercase or lower case.

Answer 3

How can we find palendrom in c

Answer 4

Case sensitive means for only characters use upper case or lower case