Can't find a definite answer online to my specific question sorry if its been asked.

My bike tire size is 700 x 28c, I bought tubes online that are sized 700c x 28'', I opened the box and the tubes look pretty fat.

My question is specifically, are 700 x 28c and 700c x 28'' completely different tube sizes? Would they fit the same tire?

Thanks a lot

You're missing something...700c and 28" are the same thing. They refer to the rim diameter. 700c x 28mm is a diameter AND a width. It's not '28c'. The 'c' is supposed to go with the 700, or 650. There must be another measurement on the tube box...usually a range from say 28-38 or 20-28.

The tire and tube I use for sure says 700 x 28c, and this different 700c 28'' tube just says SV 17 60mm

May be the stem is 60mm. Hence the 60. As for 28mm tire width if there are no other markings lay the tubes next to each other and see if they are close. Most tubes fit a range of widths. Like 25mm to 28mm. Or 28mm to 32mm.

What brand of tube? Can you post a few pictures of the box.

Edit. Here are a few I have.

The Victoria on the left is for 18 to 23 mm
The Conti in the middle fit a wide range of 700 tires. 25 to 33.
The Conti on the left is the in between size.
One can use a tube outside the desired size range but more chance of a flat.

When something is labelled 28” it means 28 inches. Not 28 mm. So a 700c x 28” tube is nonsense. Tubes are usually labelled by a range of tyre widths they are suitable for eg 25-28 mm.

I know what it says on the tire and the tube and probably the boxes as well. It's not the 'correct' terminology but gets used anyway. I'm trying to explain to you what it means.
700c and 28" are referring to the same thing, the diameter of the rim. 28c refers to the width of the tire and tube. The 60mm is no doubt the length of the valve, SV being Shrader.

If it is “700 x 28” then it a 28mm width tube. Lay the tubes next to each other to compare.

Yeah, some tire manufacturers do that. Doesn't mean it's right, though. As far as I'm concerned, they should just throw out all those archaic tire/rim size designations and leave only the unambiguous ETRTO/ISO size designations.

If it's a Schwalbe tube, the "SV" would mean Sclaverand, aka Presta.

Except for that...yep.

When they put a "c" after the width of a tire, that is to denote that it is for a crochet or hooked rim.