Moisturiser - lotion, fluid or cream!?!

[Jemster]

I need a new moisturiser, something more moisturising than what I have been using as my skin feels tight even after I put it on.
Looking in Boots but there are so many to choose from. What is the difference between the creams generally in square boxes & the lotions or fluids in the tall boxes?

cream is the thickest, lotion is the thinnest. Lotion doesn't tend to have spf in it but is very light.

I like gel formulas

I'm using a serum (Soap & Glory in the tube with the pump top) I don't like anything greasy , makes my glasses slip.

If you get something too thick, it'll roll of into little bits (which is a pain )