PEE stands for Point, Explanation, Example
PEEL is the same as above but with an added 'L' for Link
PEE is usually preferable for answering exam essays.
In an exam you are fairly limited in how much you are able to write. Therefore this is an easy structure for ensuring that you recieve marks for factual knowledge, understanding and argument structure, in each paragraph.
PEEL is usually preferable for writing longer pieces of coursework.
Link the paragraph you have just written back to the question you are answering. This prevents you from diverging off topic and demonstrates to the reader that you understand exactly how each point you make supports your argument. Another option is to write a sentence linking your paragraph to the next. This ensures that your argument flows nicely and is useful, in a more complex argument, where your main points don't fit neatly into single paragraphs.