What is wajib in islam?
Wajib is something that has been commanded in Islam. The verse “And establish prayer and give zakah” (Baqarah 43) is an example. According to this verse, all mukallaf Muslims must perform the five daily prayers and pay the zakat tax. The term “fard” and “wajib” are interchangeable.
Types of wajib acts: Wajib acts, according to upon whom it is obligatory, is divided into two type; wajib ‘ayn and wajib kifaya.
a-Wajib ‘ayn (fard ‘ayn): These are personal obligations that every mukallaf is required to do. For example: five daily prayers, praying the zakat, fasting during Ramadan etc.
b-Wajib kifaya (fard kifaya): These are social obligations that every person is obliged to do until enough people have fulfilled it. After enough people have carried out the wajib kifaya, it is no longer an obligation for the rest. If no person fulfils this wajib, all those who did not carry it out (due to negligence) are responsible and thus have sinned. Example; funeral prayer, replying to a Salam greeting, carrying out “al amr bil ma’ruf wa an-nahy ‘an-il munkar”, going to jihad, studying medicine etc.
Source: Fiqh1 (According To The Maliki School Of Islamic Law), Erkam Publications