Affect and effect are two words that easily get mixed up
Affect is mainly used as a verb. It means have an impact on, have an effect on.
The bad weather affected our plans for the evening.
The old man was visibly affected by the girl’s kind words.
How will the strike affect your job?
Affect can also have the meaning pretend to be or have.
I don’t like how he affects a British accent.
Effect is a noun. It denotes the result of an action or an impression.
The effect of his words was immediate.
I liked the sound effects in the film.
The law is still in effect.
To sum up, most often affect is a verb and effect is a noun.
That said, you may – on rare occasions – find affect used as a noun. Then it means something that acts on something else, usually in psychological jargon.
And effect can be used as a verb meaning to produce, bring about something new, often in phrases like ”to effect a change”
Read about effective and efficient here.