Answer:
self accepatnce is when you have learnt to accept yourself and love yourself for who you are and what you have. When you accept yourself and not try to change yourself for other people, is when you won't be able to be put down by anyone else.
Self improvement is when you try to look better or change yourself according to society or what your peers have pointed about you. Self improvement is always trying to change yourself or 'improve' yourself to fit into someone else's standards and anything they say will get to you.
For example, if someone tells you that you look fat or overweight, then if you take that to heart and try to become really skinny, starve yourself, isolate yourself and let it get to you, then this is self improvement, as you are changing yourself to change someone elses opinions on you.
However, if you have self acceptance, then you won't take that persons rude comment to heart, you will ignore them and not let it get to you, and carry on with what you are doing and be happy in life.
It is important to self accept yourself because you shouldn't change yourself for someone else and suffer that way, self love and self acceptance comes before everything in order to stay positive in life.
