Why is it called Western blotting? And this whole Southern and Northern blot thing, is it just an example of a bunch of scientists’ bad sense of humour?
Well, sad as it may be, the answer is pretty much… yep. It is. Southern blot was invented first, though, named after the British scientist Edwin Southern. While Western blot is used to separate and characterise proteins, Southern blot is used for the same purpose although with DNA, and Northern blot for RNA. Now, the whole biochemical world is waiting at the edge of its seats for someone to invent the Eastern blot… 
So what on earth is Western blotting anyway?
A scientist would probably answer that very shortly, Western blotting is a method commonly used in order to identify and quantify a certain protein, or fragments thereof, in a sample of tissue homogenate or extract. This is performed by using a one dimension SDS gel-electrophoresis, followed by transfer of the separated proteins from the gel to a membrane, and subsequent immunoblotting of the protein of interest. 

In plain English, it is a common method used in order to separate proteins and label them so that they can be seen. Thereby, it can be determined which protein or which protein fragments that are present in the analyzed sample, and how much there is of the protein in question.

Why is this important? What is the ultimate masterplan? 

Well, obviously, this is very important. A successful Western blot leads to an A+ in biochemistry, which leads to a satisfied supervisor, which leads to a science scholarship, which leads to slavery laboratory work at the institution basement, which leads to publications for the institution (where your name is “accidentally” forgotten), which leads to more money for the institution, which leads to more exciting tasks for you, which leads to a publication in Nature (with your name on it!), which unavoidably leads to a star at the Walk of fame, free lunches at the Chateau Marmont and ultimately the Nobel prize. Now, see why you should read on?