Protein Isolate

Both come from milk whey. An isolate is filtered further, which raises its share of protein and lowers the share of other milk components such as lactose and fat. How large the difference is depends on the product, so compare the protein, carbohydrate and fat per 100 g in the nutrition tables.

Not automatically. Filtering removes most of the lactose, but an isolate can still contain some. If you need to avoid lactose, check the nutrition table and the label of the exact product for a lactose statement.

A whey isolate made to mix with water into a clear, light drink instead of a milky shake. Clear isolates are usually fruit-flavoured; compare their protein per serving and per 100 g like any other isolate.