You enrol to vote and turn up to cast your ballot when there is an election.
A summary of differences between Au. and USA:
1. We don't have set dates or years for elections. Both State and Federal elections have their own cyles; Federal is three years, give or take and State is four years. We often have early elections, but never (I think) a late one.
2. Elections are always on a Saturday, although early and postal voting take place.
3. Technically, we know roughly when an election is due, but not until the date has been called are we sure. Campaigns tend to be three or four weeks, a long campaign is six weeks. I've joked in the past about the US being in a constant state of election but tfg's announcement kinda proves it.
4. I guess the main difference is in culture and attitude; we turn out to vote because that's the way we do things. Technically, you are required to turn up to the polling place, have your name crossed off and be issued with a ballot paper. However, you could stuff it in your shoe, eat it or throw it away. No one forces you to actually mark the paper/s. I don't think many people are prosecuted for failing to vote and if they are it's a few dollars fine $20 or $30 that I don't think they make a big deal out of collecting.
5. We have six states and two territories compared to your fifty states. Elections are run by the Federal Australian Electoral Commission and the mechanics, equipment, staffing, rules etc are consistent throughout the Commonwealth, States and Territories. We are still issued with a lead pencil and paper ballots. I early voted for the Victorian state election yesterday; nothing much has changed since I first registered to vote 50 years ago. It's real time warp stuff but sort of comforting and eternal too.
6. I would imagine that the logistics of running an election are easier when you can accurately estimate the numbers who will turn up. Yesterday, being the second day of early voting, I had to wait for - five or six minutes in a queue.
7. When you turn up at the table in the voting place, you are asked your name and your address. That's it. No signature, no proving identity - nothing else. They ask if you've voted anywhere else this day, cross your name off and issue your ballot/s.
That's about all I can think off. Sorry this is a bit fragmented and wandering. Feel free to follow up with any specifics that interest you. Almost forgot to mention, there's an Aussie tradition on election Saturdays. There's alway's a sausage sizzle or two at the polling places and the smell of fried onions perfumes the air!