“Effective” is an adjective describing everything that has a desired or specific result. It is usually accompanied by a large number of abstract nouns as well as nouns referring to people and activities. For example:
Learning online is an extremely effective solution for those students who do not have the opportunity to attend English classes in their nearest neighbourhood.
Anna is one of the most effective teachers our school has ever had.
“Effective” is also used as a synonym to “operational”. We can use it to speak about laws that become binding in a given period:
The new law will become effective in the next few days.