I say, and with God's success: The types of I'tikaf are as follows:

First: Obligatory I'tikaf: This is the vowed I'tikaf, whether the vow is explicit, such as saying: 'I have vowed to perform I'tikaf for such and such,' or conditional, such as saying: 'If God heals my patient so-and-so, then I will perform I'tikaf for such and such.'

Second: Confirmed Sunnah I'tikaf: Such as the Taraweeh prayers in the last ten days of Ramadan, as a means of fulfilling the rights of the mosques, which can be achieved by the actions of some, just as the purpose of the funeral prayer is to fulfill the rights of a Muslim, which can also be achieved by the actions of some, even if it is an individual.

Third: Recommended I'tikaf: This can be performed at any time except for the last ten days of Ramadan. If a man performs I'tikaf without making it obligatory upon himself, he is considered to be in I'tikaf as long as he remains in the mosque, and if he interrupts it, there is no penalty upon him; because he has stayed in a specific place, and it is not measured by days. Refer to: Al-Tahbiin 1: 347, Al-Mabsut 3: 121, Al-Hadiyah Al-Alaiyyah p.183, Al-Waqayah p.244, Al-Insaf in the Ruling of I'tikaf p.41/42, and the Jurisprudential Method of Imam Al-Laknawi p.286, and God knows best.