also: にっぽんぜい
noun
Japanese contingent; Japanese competitors; Team Japan
Refers collectively to Japanese participants in an international event, such as athletes, companies, or delegates. Often used in news reports about sports, business, or politics.
オリンピックで日本勢が金メダルを獲得した。
The Japanese contingent won a gold medal at the Olympics.
今回の見本市には日本勢が多数出展している。
Many Japanese companies are exhibiting at this trade fair.
日本代表 specifically means 'Japan's representative(s)' or 'the Japanese national team', while 日本勢 is a broader term for Japanese participants as a group.
Compound of 日本 (Japan) and 勢 (force, group, contingent). The suffix 勢 is commonly used to refer to a group of people from a certain place or organization.