USA and Canada
The conventional idea of dating is rooted in Western culture.
Dates are seen as a way to test out a potential partner before making a commitment to a relationship. In the USA and Canada, dating starts as young as 14 or 15, although these dates are often in groups. For adults, it's common to meet potential dates at a bar -- it usually starts by the man offering the woman a drink. If they like each other, they will exchange numbers. Common date activities are going to dinner, the movies, a sports game or a bar. The man usually pays for the date, at least at first. Public displays of affection (like kissing in public) are socially acceptable.
In Central and South America, people start dating in their later teen years, and then not just in couples.
A group of friends will all go out together to go dancing or to eat out, where couples form. Casual dating isn't as common as in North America, and most young men and women take their relationships seriously.
In Asia, dating is more strict and most young people don't start dating until they are finished school, usually at around 20.
In some countries, such as India and China, marriages are often arranged. Thus young people might date a bit, but they know that they will marry the person their parents chose for them. The choice is usually made based on social status or the alliance between families, rather than romance.
In the Middle East, dating practices are heavily influenced by religion and tradition.
In Iran, dating is even illegal. Most marriages are arranged, and men and women are generally separated until they meet each other in a supervised date before marriage. This reflects a culture of stricter social norms and a stronger value on religion.
The dating practices vary widely across the continent.
In general, however, sex before marriage is not acceptable, so even when young people date, it doesn't lead to a sexual relationship. In the countries where Islam is a major religion, the dating practices are quite strict and the marriages are often arranged by the parents. In some countries, polygamy is legal and practiced, so men may court and marry a younger woman after he is already married.
The dating practices differ from country to country in Europe.
In Western Europe, dating among teenagers is usually a group activity, such as going to a party or a club. For adults, dates are more likely to be one-on-one and more formal. In Russia, dates usually happen at a dance club or a ball. In the UK, young men and women go out in groups to go drinking or dancing. Drinking can be an important factor in mustering the courage to tell someone you like them.
Intercultural dating is becoming more and more common, with the increase in immigration and the invention of online dating.
As different cultures come in closer contact with each other, many people find partners of a different culture and have to adapt their expectations or assumptions to make the relationship work. Yet dating someone with a different background can really enrich the relationship by forcing both people to communicate more, make more effort to understand each other, and compromise.