Correct spelling, explanation: provider is an agent noun, which means it’s a noun denoting the performer of an action. This is indicated by the -er suffix. This word may cause some trouble because the -or suffix is often used to create agent nouns as well. Provider comes from the verb provide, which ends in an -e. It will help you remember that you can’t spell this word as providor.

Definition of provider:
noun, one that provides something
Your country should be the main provider of your welfare.
Times have changed: men aren’t the only providers to families anymore.

Collocations with provider:
Some most commonly used collocations include: independent provider and monopoly provider.
Small independent providers often offer the best products.
This company shouldn’t be a monopoly provider: our market needs more room for competition.

Incorrect spelling, explanation: you won’t find the word providor in any dictionary, because its ending is incorrect. The right version of this noun, provider, is a derivative of the verb provide. In this case, the ending -er was used, not -or, even though both suffixes indicate the performer of some action. You have to remember that provider is the only correct spelling because the base word ends in an -e.