What's the difference between a gym and fitness?

First of all, express different meanings

1, gym: gym, gym; Sports activities, esp in schools.

2, fitness: health; Moderate environment; Fit and competent.

Second, the fixed collocation is different.

1, gym: brain gym? Mental exercise; Mental gymnastics; Brain strengthening exercise

2. Fitness: Fitness instructor? Bodybuilder; Fitness instruction.

Synonym introduction: gymnasium

Pronunciation: [dm? ne？ Son? m]

Express meaning: gym, gym.

Part of speech: usually used as a noun in a sentence, such as subject or object.

Example: that? Is it? That? Gym? Open? That? Third? Floor? Yes? Walker. ?

That was in? Walker. The gymnasium on the third floor.