The so-called blue ocean is a new product / new market / new field with little competition.

The so-called red ocean is a fully competitive market.

For example, a region has a lot of buy clothing, then this region to buy clothing industry, is a red sea, full of competition everywhere,

Low profit margins. But no one in this area to do the restaurant industry, this area of the restaurant industry is a blue ocean, you open a restaurant certainly earn.