int32 is a synonym for int.

You can use this data type to store integers that are between -2,147,483,648 and 2,147,483,647 in value. That is, you can use int32 to store signed integers that can be represented in 32 bits. The default value for an int32 is 0 (zero).

See also: int, int8, int16, int64, uint8, uint16, uint, uint64.