Signed and unsigned intergers

when a date type is considered signed and unsigned is that simple referring to - for signed and positive numbers for unsigned? Further if that is the case would mutiplying and dividing ect where 2 signed numbers, like (-2)*(-2) = 4 result in a unsigned.

When data type is signed it means that the bit order represents negative, zero and positive values, when it is unsigned it means it can represent only zero and positive values. For example signed byte can represent values between -127 and 127, unsigned byte can represent values from 0 to 255.

The difference between signed and unsigned isn't the minus symbol, it's how the numbers are interpreted by the processor.

An unsigned signed 8-bit number:

binary 1 1 1 1 1 1 1 1 = 2^7 + 2^6 + 2^5 + 2^4 + 2^3 + 2^2 + 2^1 + 2^0 = 255

A signed 8-bit number:

binary 1 1 1 1 1 1 1 1 = (-2^7) + 2^6 + 2^5 + 2^4 + 2^3 + 2^2 + 2^1 + 2^0 = -1

This allows easy subtraction as well as addition through two's-complement arithmetic -- add the opposite plus one to subract.

For unsigned interger the MSB(most significant bit) is '0'.
For signed interger the MSB(most significant bit) is '1'.

For example,(I) 12 is represented as 0000 1100
(II)-12 is represented as 1111 0100