A week is 7 days in connecting order. There are usually 52 weeks in a year.
In the English language, the days of the week are named after gods in Norse mythology, except for Saturday, which is named after a Roman god.
Depending on the law of a country, the week either starts on Monday and ends on Sunday, or starts on Sunday and ends on Saturday. In most countries, Saturday and Sunday are the weekend. Friday, Saturday, and Sunday is a religious day for Muslims, Jews, and Christians, respectively.