What is the difference b/w signed and unsigned integer datatype?

Answer 1

signed can be a minus value (- sign)
unsigned is positive only

Answer 2

Think of it like this, it is a data type modifier. Signed means exactly that, the data type is signed (having a negative value (-9 for example), or can have a negative value), where unsigned, again means exactly what it implies (a positive only value (9 for example)). It's an honestly easy concept, just you gotta remember it ^_^

Answer 3

signed int: from −2.147.483.648 to 2.147.483.647
unsigned int: from 0 to 4.294.967.295