What's the purpose of u s navy sister ships to each other?

Question

what kind of bond or relationship does 2 navy sister ships have to each other.

Answer 1

it simply means they are ships of very similar designs.  A CLASS of ship gets its name from the first ship of the series.  So for example, the NIMITZ class are all aircraft carriers using the same basic design as the first of the series, the USS Nimitz.