What’s the difference between a prokaryotic and a eukaryotic cell?

This is a topic which is common across all A-Level specifications, the questions surrounding this topic may vary from labelling diagrams, matching features in a table, or longer written styles of question (like the example here).
Step 1:
Look at the key words, in this particular question the examiner is asking us about the differences between prokaryotic and eukaryotic cells.
Step 2:
Think about features in both prokaryotes and eukaryotes, e.g. which organelles are found in each... 
A great way of learning this is to draw out diagrams, or learn a mnemonic for both types of cell
Step 3:
List your differences…
-Eukaryotic cells have membrane bound organelles (e.g. mitochondria)
-Prokaryotic cells do not have membrane bound organelles.

-Eukaryotic cells have a nucleus containing their genetic material/DNA.
-Prokaryotic cells do not have a nucleus, the DNA is free-floating.
-Eukaryotic DNA is linear and is associated with histone proteins.
-Prokaryotic DNA is circular (in a loop), and is not associated with histone proteins.
-Eukaryotes have larger ribosomes (80S).Prokaryotes have smaller ribosomes (70S).Prokaryotes have a cell wall made of murein.
-Prokaryotes may have additional features that eukaryotic cells do not have, e.g. flagella, pili, or a capsule.

A great answer will look at and compare both prokaryotic and eukaryotic cells, not just give features of one cell type. 
A great answer will look at how many marks the question is worth, and give one difference for each mark, this means each of the above pairs is worth one mark.