"Affect is usually a verb, and effect is usually a noun. To affect something is to change or influence it, and an effect is something that happens due to a cause. When you affect something, it produces an effect. Here are a few examples of the words used correctly in these senses:
The storm knocked down power lines, affecting several thousand people in rural communities. [CBC]
Gauging the disaster’s effect requires assessing economic activity that might be lost. [Wall Street Journal]
The regulator has estimated that its new rules will affect up to 11.3pc of borrowers. [Telegraph]
But the smell of freshly baked bread may have positive effects far beyond the obvious ones. [Independent Online]"
Hope this clears things up.