One radian is the angle of an arc created by wrapping the radius of a circle around its circumference.
1 radian is equal to ~57,2958 degrees.
Converting from radians to degrees (and vice versa) is pretty straight forward and it can be done using this two formulas.
degrees = radians * (180 / PI)
radians = degrees * (PI / 180)
A chart to convert between radians and degrees:
Most of the time you’ll find that trigonometric functions in different programming languages (C#, PHP, Python, etc.) use radians as input arguments although it’s much more frequent to use degrees to express angles in real life (latitude, longitude, declination, etc.)
This is when converting from radians to degrees and vice versa gets useful.