I've got many seeds that look the same but have different 'parents'...Will I get the same plant from them?...Or despite their identical look,it will result different plants??

Some seeds look identical, so it they are from different parents i think you will get different plants.

I'm not to sure though.

There are far more species than there are seed types, and many look-alike seeds will produce slightly different species. The plant type will always be the same, but the flowers could be different. For example, a seed for a Spotted Maranta will look the same as a seed for a Bluestar Maranta.

Identical looking seeds can produce different plants. i.e. a small brown ball can produce five different plants (Citrus Maple, Spotted Maple, Bluestar Maple, etc.)

In addition, sometimes two completely different sets of parents will produce seeds that will result in the same plant!

As one of the "Faucet Tips" says:

Ok!Thanks for the explanation!I now know that I mustn't throw half of my seeds...