Typically, yeshiva students hear one shiur each day, delivered by the rosh yeshiva or a maggid shiur (literally, "sayer of the shiur"). Before the shiur, a bibliography and a series of textual references are posted so that students may prepare for the lesson in advance. After the shiur, students spend additional time reviewing and clarifying the lesson that they have just heard. These preparation and review periods take place in a special time period called a seder, in which students study the lesson individually and/or in chavrutas (learning pairs).
In modern parlance, the term "shiur" has been extended to include any kind of Torah lesson — including lectures to children, women, and baalebatim (non-scholarly audience), and taped lectures circulated via cassette tape, computer hookup, MP3 or MP4 connection, or call-in telephone lines. Though by definition, a shiur is a comprehensive, structured lesson, some kiruv organizations advertise "five-minute shiurim" to attract beginning listeners
Along the same lines, a shiur is also the name given to the different class-levels in a yeshiva. For example, first-year students in a yeshiva ketana or yeshiva gedola are said to be in "Shiur Aleph"; second-year students are in "Shiur Bet"; third-year students are in "Shiur Gimmel, etc. In kollelim, the higher shiurim accommodate more advanced levels of learning.