What is the difference between maintain and manage?

Manage: ntransitive and transitive verb achieve something with difficulty: to succeed in doing something, especially something that seems difficult or impossible

• I finally managed to open the door.

Administer or run something: to be in charge of something such as a store, department, or project and be responsible for its smooth running and for any personnel employed

• manages a department of 25 people

Handle and control something: to handle and keep control of something such as a weapon or tool

• could manage a computer without difficulty

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Maintain :

Make something continue: to make a situation or course of action continue in the same way as before

• maintained a semblance of normal procedures even with half the staff out sick

provide somebody with financial support: to provide somebody with the money required for a reasonable standard of living

• She maintains a big family on a tight budget.

speak in favor of something: to defend an opinion, idea, or argument against criticism

• The governor continues to maintain his position on cleaning up the environment.

Hope it defines the meaning and difference. or improve it.