Refers to a person, company, or entity that competes directly with another in business, sports, or other competitive contexts.
In this market, there are many competitors, so it's tough.
He is my biggest rival.
A loanword from English 'rival', often used in personal or dramatic contexts, while 競合相手 is more formal and business-like.
Very similar meaning, but 競合相手 emphasizes direct competition in the same field or market, while 競争相手 is a broader term for any opponent in a race or contest.
Compound of 競合 (competition, rivalry) and 相手 (partner, opponent). The word is a straightforward combination of its parts.