How did competition between european countries such as portugal and spain affect overseas exploration and expansion?

Competition between european countries such as portugal and spain affect overseas exploration and expansion, they didn't want to go to America, they both wanted to go to Asia, and Africa, trade with asia, get their riches, improve technology and covert people to Christian. Christopher Columbus wanted to go to Asia when he found america, as a result of all that competition, spanish and portuguese established colonies in america.