competitor
A person or group trying to win against others.
A competitor is someone who tries to win or do better than others in a contest, sport, business, or any activity where success matters. When you run a race, everyone else running alongside you is a competitor. When two restaurants open on the same street, they become competitors for customers.
While competitors want to beat each other, they also push each other to improve. A chess player who faces tough competitors learns to think more strategically. A student with strong competitors in the spelling bee studies harder. Without competitors, athletes would have no one to race against, and businesses would have no reason to improve their products.
Being a good competitor means playing fair and respecting your opponents. You can be competitive (wanting to win) while still being gracious. After a basketball game, competitors shake hands. When a science fair ends, competitors often ask each other questions about their projects.
In business, competition between competitors usually helps everyone: companies lower prices, improve quality, and create better products when they're competing for customers. That computer or phone you use exists partly because tech companies compete to build the best devices.