US Lecturers
A lot of American universities have lecturer positions whose role is to teach education to undergraduates. However, professors have a permanent tenure which includes responsibility into research.
Many US lecturers are themselves graduate students who may be taking courses which lead to PH.D dissertations.
A full time position in North America would usually involve courses which require a lot of teaching and very little time for doing research.
Some academics who want to a position as a junior faculty might choose to work as a lecturer first, so that they can gain the teaching experience required to qualify them for a full time job at a university. This position is normally of a lesser standard to that of an entry level professorship.