is means that the variable p gets the value from variable c assigned to it. So if c = 6 and the program executes p = c p will also be 6 but depending on the kind of variables p and c are it can also be c = "i am c" and than after p = c the value of p will be "i am c"
a b means return true if the value of a is equal to the value of b, otherwise return false. a = b means assign the value of b to the variable a.
I am guessing you typed the question wrong, the way I understand your question is "Why is the programming language named C++ and not C ? " The answer to this is that there is a programming language called C, and in that programming language the ++ means increment by one. So C++ is the language C improved, as such it can read and compile all C programs in addition to having other features that C does not have.
No, the first is a number (0x91), the second is a pointer.
c means the speed of light. It is a constant.
C is case sensitive, which means that, for example, $var and $VAR are not the same variable.
Presumably C means circumference and R means radius? If C = 2*pi*R Then R = C divided by 2*pi
Coding constants in c means writing the constants in a certain way that the c language understands.
In the C language, the ++ operator increments the operand. Thus C++ is a shortcut that means C = C + 1. Thus C++ literally means the successor to C.C++ was originally named C with Classes in 1979. It was renamed in 1983.
The fundamental difference is that in C++ object-oriented programming (OOP) was added. C is a procedural language (that means. top-down structure design), where as C++, which is an extension of C itself, is an object oriented language.
"C" is the standard abbreviation for the speed of light, which is a huge number.
C means lots of things. It is the 3rd letter of the alphabet. It is a vitamin which prevents scurvy. It is a programming language. It is a passing grade, but not a particularly good grade, being inferior to A and B. It is all these things and more.
C-language was derived from B-language.