UK citizens do not need a visa to enter Israel. On entry, visitors are granted leave to enter (by means of a stamp in the passport) for a period of up to three months. Your passport must be valid for at least six months or you may be refused entry by Israeli immigration authorities.
Those who want to work in Israel but who are not granted an immigration visa under the Israeli Law of Return (Aliyah) need to obtain a work visa. It is illegal to work in Israel without one. For further details see the Israel Ministry of Foreign Affairs .
Student visas are granted to those who want to study in Israel. The visa is valid for up to one year and for multiple entrances and exits. Recipients of a student visa are not allowed to work.
If you are not a UK national, check whether you need to obtain a visa to visit Israel. See the Israel Ministry of Foreign Affairs website for details.