What does int mean in C language and what is unsigned and signed integer __c language

int is an integer type that defines the type of variable, signed,unsigned int is an unsigned integer type, and it is straightforward to say that a signed unsigned integer is a negative number.
The number of bytes defined by the shape is different depending on the program compiler. In the C language of Class 51 MCU, int represents 2 byte (16 bits), and in the C language of 32-bit ARM processor, int represents 4 byte (32 bits).  (for example, 32-bit XP) defines an int as 4 byte (32 bits). Take a look at the range of values. In a 32-bit system, signed int A, then a range [ -2^31, 2^31-1] is [ -2147483648,2147483647].
So an int definition needs to be aware of several aspects, one is the type, the other is the size range of the stored data.