The $``\vec{w}h\alpha\mathfrak{t}\;\; i\mathbb{S}\ldots\text{?''}$ Seminar is a cycle of talks organized each semester by students at the three universities of Berlin, the Freie Universität Berlin, the Humboldt-Universität zu Berlin and the Technische Universität Berlin. Each talk of the $``\vec{w}h\alpha\mathfrak{t}\;\; i\mathbb{S}\ldots\text{?''}$ Seminar is characterized by the following:

- It lasts around half an hour.
- It introduces a mathematical idea or object answering a question of the form “What is...?”.
- It is directed to mathematics students or mathematicians unfamiliar with the exposed field.
- It happens in an open and relaxed environment where comments and questions are welcome.

The $``\vec{w}h\alpha\mathfrak{t}\;\; i\mathbb{S}\ldots\text{?''}$ Seminar takes place almost every Friday of each of the semesters either as a prelude to a MATH+ Friday Colloquium or as a stand-alone talk by a student wanting to speak a particular topic. The talks usually take place at 13:00, although there can be variations for those sessions that happen on a Friday without a colloquium.

When the seminar takes place in person, there are four primary locations:

- Urania Berlin (Ur). [$\mathcal{D}$irections]. This is the usual location when the $``\vec{w}h\alpha\mathfrak{t}\;\; i\mathbb{S}\ldots\text{?''}$ Seminar takes place before one of the MATH+ Friday Colloquia.
- Freie Universität Berlin (FU). [$\mathcal{D}$irections]. Usually at either the building at Arnimallee 6 or the one at Arnimallee 2 of the
*Institut für Mathematik*. - Humboldt-Universität zu Berlin (HU). [$\mathcal{D}$irections]. Usually at the BMS Seminar Room (RUD 25 1.023), in the first floor of the
*Institut für Mathematik*. - Technische Universität Berlin (TU). [$\mathcal{D}$irections]. Usually at the BMS Seminar Room (MA212), in the second floor of the
*Institut für Mathematik*.

However, the talks can take place in other places on exceptional dates.

The $``\vec{w}h\alpha\mathfrak{t}\;\; i\mathbb{S}\ldots\text{?''}$ Seminar receives the support of the

which is the the graduate school of mathematics of the three univeristies of Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin and Technische Universität Berlin. The BMS provides the $``\vec{w}h\alpha\mathfrak{t}\;\; i\mathbb{S}\ldots\text{?''}$ Seminar with video equipment, seminar rooms and funding for several events.