The basics

A Senator is a member of the Senate, the upper house of federal Parliament. Unlike Members of the House of Representatives (who each represent an electorate of about 120,000 people), a Senator represents an entire state or territory.

There are 76 Senators: 12 from each state, and 2 from each of the ACT and Northern Territory.

What they actually do

• Review legislation — every bill passed by the House of Representatives must also pass the Senate to become law.
• Debate and amend bills, often forcing changes the House didn't want.
• Scrutinise the government through Senate committees and Estimates hearings.
• Represent their state — protecting state interests against being overruled by more populous states.

How long they serve

State Senators serve 6-year terms, with half elected every 3 years. Territory Senators serve 3-year terms aligned with the House.

Why the Senate matters

No single party usually controls the Senate, so the government must negotiate with crossbenchers or the opposition to pass laws. This is by design — the Senate is often called the "house of review".