The best way I found to get my head around classes and id is to think about objects.
For example, imagine a chair. When you think about chairs, there are many different types of chairs. There are swivel chairs, high chairs, reclining chairs, stools, sofas. Even though they're all different, you still classify them all as 'chairs'.
So in this case, 'chair' would be the class. It's common attribute would be the fact that it's something you use to sit in. It's unique attributes would be it's colour, shape, size etc. These would be in the 'id'.
With this in mind, only turn both 'homesocialtopcell' divs into classes if they share the same attributes (eg, height, width, color etc). If they don't, make them unique ids - 'homesocialtopcell1' & 'homesocialtopcell2'.