Difference between signed and unsigend data types

Signed Data Type - a signed data type is one that can hold both positive or negative values, i.e. -1 or +456. A 32 bit signed integer can hold the range -2147483648 to 2147483647

Unsigned Data Type - Unsigned data types can only hold positive values.
An unsigned 32 bit integer for instance can hold the range 0 to 4294967296