First of, writing in all upper case is seen as yelling and will be considered rude on a forum like this, so if you would like to get help, you should refrain from that.
Secondly, yes, the Intel Galileo can be used to control the supply to electrical devices. With the information given it's not possible to say how many, but depending on the method used for control, the number GPIO pins could play a role.
It highly depends on what kind of devices, and how fast you need to turn things on and off.
If you need to control a lot of devices, but not that fast, it could make sense to use a bus model (e.g. i2c) and use only very few GPIO pins on the Galileo.
Please explain a bit more about what you want to control, so that we can better help you.
In theory, you can hookup hundreds or maybe even thousands, but you will need some additional components.
What those components should be depends on what you are controlling.
When you say "electrical devices" what is that? is it the lamps in you home, tiny little LED's, a motor or what?
The Intel Galileo board can only supply very small currents on the output pins, so if you want to control anything thats more powerful than an LED, you will need to use some sort of driver circuitry, and that needs to be designed to fit your load (the lamp, motor, etc.). Even bigger LED's will require a driver of some sorts.