Idol worship
Idolatry is the sin of believing that a statue or idol is a god, and should be worshipped. Jewish people and many Christians do not practice idolatry, as it is specifically forbidden in the Second Commandment of the Old Testament of The Bible. Islam, also, strictly forbids idolatry, to the extent that any artistic depictions of human beings are avoided by devout Muslims on the grounds that they are images that may tempt them to idolatry.
Idolatry is a sin to these believers because it localises and particularises God, who should be viewed instead as infinite, spiritual, and beyond human depiction. Idolatry relates to the sin of practicing magic, in that it puts the Divine in earthly form and subjects it to human manipulation. For some, the belief that certain objects or places are sacred or holy, the reverence paid to images or icons of saints and other religious figures, the practice of pilgrimages to remote places where religiously significant evens occurred, are all forms of idolatry. They suggest that certain objects and places have mana, that they have religious power not present elsewhere, and that prayers in the presence of these objects or places are likelier to be heard than elsewhere. This is the essence of idolatry considered as a sin.
Generally speaking, religious faiths that practice what Jews, Christians, or Muslims consider "idolatry" do not consider themselves as practicing "idolatry." Idolatry is used mostly to define a religious practice which is considered something to avoid. Those who accept the veneration of images and objects do not proclaim themselves willingly to be idolators.
One way of viewing idolatry is as a form of animism which expresses the belief that all objects in the world are alive, and thus have indwelling souls, and thus should be worshipped.
A contrasting view of idolatry is that the statue or idol is the physical form of a god who holds power over some aspect of the world, such as a particular stream of water or rain in all its forms.
Shintoism is a religion which worships images. Hinduism, which is widely accused of practising idolatry, actually simply uses idols to represent God the way Christianity use icons and paintings in churches.
Worship of idols generally occurs in temples, although many adherents have small shrines in their homes or places of business.