Spain and portugal entered the fifteenth century as two of the most powerful nations in europe. why did they choose to colonize so far from their homelands?

Spain and Portugal in this period were both strong sea forces. They were choosing far away territories for colonizing from few reasons:

1. To avoid competition and battles with the other strong countries that were also colonizing parts of the world.
2. Were targeting territories were the resistance can be easily shut down, thus gaining control in an easier manner.
3. They were trying to find new territories from which they can benefit from the natural resources of the same.

Im migration prohibition.