The typical structure is 3 years for the bachelor's degree and 2 years for the master's degree. In many countries, master's is the primary undergraduate degree, while bachelor's is considered a glorified dropout.
American undergraduate degrees often have plenty of classes unrelated to the major/minor subjects, while European degrees tend to be more focused. In some countries, those breadth requirements are considered a part of secondary education. While an American nominally starts a four-year degree at 18, a European may start a three-year degree at 19.
As for PhDs, they were traditionally considered more like certifications than degrees. You could graduate quickly if you managed to finish your thesis, but it was far more common to continue working on it well into your 30s. This has changed in the past decade or two, as universities started favoring short "American-style" PhDs, with the ideal to graduate before 30. (The British with their short PhDs were always an exception to this.)
American undergraduate degrees often have plenty of classes unrelated to the major/minor subjects, while European degrees tend to be more focused. In some countries, those breadth requirements are considered a part of secondary education. While an American nominally starts a four-year degree at 18, a European may start a three-year degree at 19.
As for PhDs, they were traditionally considered more like certifications than degrees. You could graduate quickly if you managed to finish your thesis, but it was far more common to continue working on it well into your 30s. This has changed in the past decade or two, as universities started favoring short "American-style" PhDs, with the ideal to graduate before 30. (The British with their short PhDs were always an exception to this.)