Whats the difference between the two .

The  difference is size. A cove is often referred to as a bay.. a cove is typically a circular inlet with a slim entrance. 

Down here a "cove" usually has a creek running through it.

According to the dictionary, Bay definition, a body of water forming an indentation of the shoreline, larger than a cove but smaller than a gulf. But similar to Catt, to me, a cove is more long/deep than wide and frequently has a larger secondary creek running through it, while a bay is more of just an open water protected pocket (large or small), about as wide as it is deep/long, often containing a larger percentage of shallower water (as in, "spawning bay"), and frequently containing smaller drains as opposed to one large creek channel.

-T9

Most bays in my area have several coves.

Here is Irondequoit Bay (I refer to it as the city dump in my reports...), off Lake Ontario (to the north).  There's at least 20 coves on this four mile long bay.  The entire bay is fed by 4-5 creeks, though the main tributary to the south is Irondequoit Creek.

If you Google Maps Irondequiot Bay, and scroll west to Braddocks Bay, you'll see a Bay that is much more open to the big lake, but also has several coves.  Go to the east, and there are a few more..Sodus, East, Port, Fairhaven, even Chaumont on the far eastern side of Lake Ontario.  Those would be my best examples.  For a smaller lakes with bays, and coves, take a look at Oneida to the east, or Chatauqua to the west.

Where I grew up at Big Bear lake our cabin was on Canvasback cove part of Mallard bay  off Sleepy lagoon. Big Bear has Papose bay, Boulder bay, Metcalfe bay, Fawnskin bay and Mallard bay, everyone of those could be called coves in another region.

Tom

Around here we call a small cove a pocket.

12 minutes ago, Bankbeater said:

Around here we call a small cove a pocket.

How small is small? Pockets for some bass anglers aren't any bigger than a casting distance.

Canyons in mountain regions are sometimes called coves, pockets being open spaces within the canyon or cove, just depends where you are from.

Tom

1 hour ago, WRB said:

How small is small? Pockets for some bass anglers aren't any bigger than a casting distance.

That's about the size of what I call a pocket.  You can cast all the way to the back of it.  I anchor the boat and fish them really thorough.

GodBless & Thanks , i think i got it .