The Holy Land refers to the Land of Israel. Jews as well as non-Jews have traditionally referred to this area as "Palestine", as in the 1759 map (attached) which calls it "The Holy Land, or Palestine ... (with) the Ancient Kingdoms of Judah and Israel in which the 12 Tribes have been distinguished"
The term is also used by Muslims and Christians to refer to the area between the Jordan River and Mediterranean Sea i.e. it includes modern Palestine as well as Israel.
Part of the significance of the land stems from the religious significance of Jerusalem, the holiest city to Judaism, the assumed place of Jesus's ministry, and the Isra and Mi'raj event in Islam. The perceived holiness of the land to Christianity was part of the motivation for the Crusades, as European Christians sought to win the Holy Land back from the Muslim Suljuq Turks. They had taken it over after defeating the Muslim Arabs, who had in turn taken control from the Christian Byzantine Empire.
Many sites in the Holy Land have long been pilgrimage destinations for adherents of the Abrahamic religions, including Jews, Christians, Muslims, and Bahá'ís. Pilgrims visit the Holy Land to touch and see physical manifestations of their faith, confirm their beliefs in the holy context with collective excitation, and connect personally to the Holy Land.