verb
BAD : To accomplish world unity, we need peace.
GOOD : To achieve world unity, we need peace.
BAD : A balanced diet is accomplished by eating many different kinds of food.
GOOD : A balanced diet is achieved by eating many different kinds of food.
◆◆◆
When you accomplish something, you manage to do it or complete it, especially something that gives you satisfaction: 'She felt that she could accomplish more through journalism.' 'During his five years as President, he accomplished very little.'
When you achieve something, you manage to do or obtain what you have planned to do or obtain, especially after a lot of effort: 'The company intends to achieve all these goals within the next five years.' 'By the age of twenty, she had already achieved her ambition.'
Note that achieve is also used to mean 'accomplish': 'By the end of the course, you will feel that you've really achieved something.'