What does Signed and unsinged mean

Answer 1

Signed values can be negative, unsigned values can't but have twice the space for positive numbers as a result.

For example, on a 32-bit architecture:
An int variable can take values from -2,147,483,648 to 2,147,483,647.
An unsigned int variable can take values from 0 to 4,294,967,295.

Answer 2

when you declare a signed so its mean that you are using the positive and negative numbers and when you are using the unsigned which means that you are only using the positive numbers, so when you are using the unsigned so you get a range between the negative and positive but when you are using the signed so these negative numbers are cancelled and the positive number range become double. This data type is used when you know that your number is how much big in positive and if negative so you used signed

Answer 3

yes