In general business terms, turnover is the rate at which employee's resign or are terminated in a given time period. If a company is hiring a large amount of people, but is not increasing the amount of positions within the company, they would be said to have a high turnover rate. If the company was firing (or people were quitting) and the company was not replacing them, the company would be contracting or downsizing. If the company was opening new positions and that is the reason for their increased hiring, the company would be growing or "expanding".

depends on what turnover you are referring to. For example inventory turnover, it is how fast inventory become cash in a certain period. If employee turnover, how fast you gain and lose employees. turnover is how many times the cycle is. hope you get the point.

It could mean anything.

If talking about company income turnover is the total value of sales.

Or you could be talking about the number of cans of baked beans you eat per week.

This depends in what 'context you are looking.

In many cases 'Turnover' is simply 'total value of sales', Not to be confused in any way with 'profit'.

Same as Revenue or Sales. Top line on the income statement.

the amount of employees leaving and being replaced