Why do U.S. representatives serve shorter terms than U.S. senators?

What does this answer mean?

U.S. representatives serve shorter terms than senators to more closely follow public opinion. Because every House member has to run for election every two years, voters can quickly replace representatives who don't reflect what the people in their district want.

The two parts of Congress were designed to work differently. The House was meant to stay close to the people, with frequent elections. The Federalist Papers argued that the House should depend directly on the people and share their concerns, and that frequent elections were the surest way to make that happen.

The Senate was designed to be steadier. Senators serve six-year terms, and only about one-third of the Senate is elected every two years, so it changes more slowly. Until the 17th Amendment in 1913, senators weren't even elected directly by voters; state legislatures chose them.

At the interview, say "to more closely follow public opinion." The key words are public opinion.