Hajj means going to Mecca to perform tawaf (circumambulating the Ka'bah) and the rest of the rites during the months of hajj in response to the command of Allah and seeking His pleasure.
Dar al-Iftaa al-Misriyyah
he Hajj, or the Muslim Pilgrimage to the Holy Places in Mecca and Medina, is not merely a religious undertaking of devotion for Muslims; it is a global annual event that included political, social, economic, and intellectual
It is obligatory according to the Book of Allaah and the Sunnah of His Messenger, sallallaahu ‘alayhi wa sallam, and according to the consensus of the Muslims. The Prophet, sallallaahu ‘alayhi wa sallam, said: “Allaah has enjoined the Hajj upon you, so perform Hajj.” And the Muslims are unanimously agreed upon that. It is something that no Muslim has any excuse for not knowing. Whoever denies that it is obligatory and he is one of those who live among the Muslims, is a disbeliever. A person who fails to do it out of negligence is in grave danger, because some of the scholars said that such a person is a disbeliever.
How to Perform the Rituals of Hajj, Umrah and Visiting the Prophet’s Masjid