There are indeed quite a few 37.5 hour jobs (I'm working one, albeit 8-4 by my own choosing, not 9-5). Especially Scandinavian countries are experimenting with shorter work weeks (down to 30 hours), though other western countries are moving down from 40 hours as well.
Lunch is in most western countries not included in the work hours, no matter the hours you work, unless you do work at the same time - e.g. meeting a customer for lunch to talk about business stuff - which is usually a case-by-case thing and defaults to not counting into your worked hours.
Most western countries include in their laws a mandatory break after a certain number of hours worked, so you generally can't work 8 hours without taking at least 30 minutes of break at some point. For example, in Germany you need to take an at least 30 minute break after working for 6 hours, so you can't work 8 hours without any breaks. Those breaks still don't count for your work hours. Work lunches don't count for those laws.
In case you are a smoker, stepping outside for a cigarette is usually seen as a break which doesn't count towards your worked hours, while going for a coffee from the coffee machine does count. That is mostly a company culture thing.
Most contracts have core hours, meaning time you need to be available for meetings and such, and flexible time around it. The core hours are usually shorter than the work hours, so you might arrive early and leave at the end of the core hours or arrive at the start of the core hours and work longer afterwards or any mixture of those. As an example, your core hours might be 9 to 5, so you could arrive 8:30 and leave at 5, with a 30 minute lunch in the middle, or arrive at 9 and leave at 5:30.
Travel to and from work is usually not included into your work hours, so the commute does not count into it. If you need two hours to get to work, you still have to work the full 8 hours (assuming 40 hour week) afterwards. Travel that is explicitly for work, e.g. travelling to an event or to a customer, usually does count towards your hours worked, though that can depend on your country and contract as well.
It gets really complicated once you start to talk about overtime. In general, for worked overtime you are entitled to the same amount of paid time off from work or (monetary) compensation for the extra time worked. Whether you can take time off during core hours or even take a full day off for 8 hours of overtime depends on the country and contract. Some contracts include phrases like "Overtime up to X hours a month is already included in the salary," which means you don't get that time off or compensation for those X hours of overtime, but you also don't have to work that overtime. Depending on the country and company, you might still be forced to work such uncompensated overtime through pressure from above (i.e. the boss forcing you to work that time).