I just want to ask a few basic questions.

1) buy and sell.
does buy means bet on the market go up, and sell mean bet on the market go down?

2) Equity and Fund
does Equity mean what you put in the market, and Fund ( I am 99% sure about Fund) means your deposit?

3)what does type G mean?

4) Australian 200 is 5765.8 , I sell 1 contract, why the Equity is 18.314, and the margin is 375?