When you have new rope and you want that rope to be used for a long period of time, you will need to prevent fraying. There are several ways to do so including using tape, tying a dead knot at the end, whipping it or splicing it. The first two are really stop gap measures if you can't afford the time or if you know the rope is not going to be used for a long time and maintainance is not critical.

However the better argument is whether to splice or whip a rope. Both techniques have advantages and disadvantages and I shall discuss them

Splicing

Splicing is good as you do not need additional resources (think thread or twine). So the back-splice is a popular option to prevent fraying.

Splicing is also good if you intend to make a permanent eye at the end of a rope.

However splicing also thickens the ends (which is a problem is the end is needed to run) and also takes tying some knows at the end impossible.

Another problem is that splicing shortens the rope (by both the part that is back spliced and the part used to be back spliced). This reduces the workable part of the rope and should be factored in if being used before cutting rope.

Whipping

Whipping usually produces a neater look and is just as secure as a splicing is done correctly. Simple whipping should be used for less thick rope and sail maker's whipping for thicker rope.

Whipping does not produce a significantly thicker end. Perhaps the only disadvantage is that you will need thread and wax to do a good job with whipping which is not needed for splicing.

So when deciding which technique to employ, weigh the pros and cons and do what is most suitable for your needs.