I'm pretty new to STO and so far I love it. One thing that I don't understand is whether or not the different ships really make a difference? When I look here on the website it seems to me that all of the ships within a certain class are all the same is this true or not? Am I missing something? Then another thing that I am confused about is how do I know what ship I have if when I'm in the game I use the ship designer to make my ship look the way I want. I ususally use pieces from all three different ships so how do I know which ship I am actually using?
Within a tier and within a class, there's no difference (with the exceptions being ships available on the C-Store). Ship customization is purely cosmetic, and doesn't affect the ship's stats in any way.
The different classes of ships, however (escort, cruiser, science) differ from each other significantly.