Understanding string comparison in C

Hi,

I am trying to understand C strings. But got puzzled with string comparison.

I have declared three string like below.
    char *str1="String1";
    char *str2="String1";
    char str3[] = "String1";

Comparision of str1==str2 is true whereas str1==str3 is false. I can't understand why so?
Can anybody help?
Full runnable code is available at http://onlinegdb.com/fork/B1mPNLqbZ

Thanks in advance.

@karambaHZP:
It doesn't answers his question.
He is about "why", not about "how".

@cnp:
I don't know why in 1st case it's true...
For me all of these are pointers and they should be different. :/
(Maybe str1 and str2 are getting same pointer to the same literal?)
(str1's and str2's types are const char* tho)

str1 and str2 are getting same pointer to the same literal

This.

str1 and str2 are getting same pointer to the same literal

Yep. And you are comparing pointers instead of string values.

I understand somewhat, str1 and str2 are getting same pointer to literal. But why "str3" getting different pointer to literal then? Is it just dependent on compiler?

str3 is not pointer

PS.
is array
You can change the content of str3

In second example you comparise something like 0011FF74 == "String1"