What is difference between angle and degree?

This is an informal answer.

Imagine an angle of 5°. It is quite small and thin. Go down to 4°, 3° 2° 1° 0° until it becomes a straight line.

Imagine another large angle of 175°, Make it bigger 176° 177° 178° 179° 180°. That's a big angle, but it is also a straight line.

In practice you can't tell the difference between 0° and 180°. In theory you can.

Someone may have an entirely different approach.