Technology and Magic
The differentiation between magic and technology in Spellgate is minimal at best in the off-world areas. Goa’uld and other alien races power their magic through the energy field known as Mana. Mana, of course, is the mystic energy that powers spells and other magic effects.
Earth is in what is called a no mana zone. In other words, it has none of this energy field in it’s immediate vicinity (meaning for approximately 1.5 LY from Sol). Beyond that range Mana levels tend to fluctuate between normal mana levels to low and very high. No mana zones are rare on a planetary or stellar system scale, but do occur in smaller scales, such as a single region of a planet or moon.
The Goa’uld are very capable scavengers of mana-based technology and have done so repeatedly over the course of their existence. However, they do not have the ability to manipulate mana very well on their own, as a true sorcerer or wizard would be able to. To cover this weakness they exploit their technological adaptation of mana use as a power source. As a result, their technology is much more efficient at siphoning off energy from the field than any species is physically able to. This has allowed them to mass produce effective technology that enhances their own foot soldiers’ ability to wield mana-based weapons.
Being in a no mana zone, humans on Earth are limited in their access to mana-based technology. However, the Stargate is also able to absorb electricity. As such, humans on Earth have found that if you provide enough energy from other sources, such as electricity, the mana-based technology will be able to absorb it and convert it into a useable form. It is still unknown how the energy is converted in this way.
The primary mandate of the SGC is to acquire this technology and develop an understanding of it at all costs.