The interesting thing is this, a One-Point Perspective Drawing is derived from a slight deviation from an Oblique Drawing. Both still have the same full 2-D front view of the object. The only difference in a One-Point Perspective is that its 3rd dimensions are drawn aligned to a POINT (wherever the artist wish it to be). The 3rd dimensions of the Oblique Drawing are simply projected at 45 degress parallel to each other. In the One-Point Perspective Drawing, when the 3rd dimension lines are drawn towards a POINT, what you have created is an illusion that objects further away looks smaller! Therefore it looks more realistic than the Oblique Drawing.
Which is better?
Alternatively you can also watch a video showing the 4 main types of drawing techniques I talked about in this post.
Just in case you are very keen, the final type of drawing technique makes use of three points and you call that a Three-Point Perspective Drawing. Ever watched Spiderman on TV or read any Marvel Spiderman Comic Book with 'Spidey' swinging from the top of the skyscrapers and the camera view showing all the actions from the sky down? Did you notice how the buildings looked like? That is a combintion of One, Two and Three Point Perspective. Cool isn' it?
Here is a FIVE-POINT Perspective tutorial link if you are REALLY REALLY keen. It is pretty easy to understand what is going on in the tutorial. Below is my very first attempt at 5-Point Perspective Drawing much later during my free time.
Let me know if you have questions.