Idolatry is any attitude and activity of prostrating before an image of value, and following it as the strength of their actions.
Thou shalt not bow down thyself to them, nor serve them: for I the LORD thy God am a jealous God, visiting the iniquity of the fathers upon the children unto the third and fourth generation of them that hate me; Exodus 20:5
It is also considered as idolatry, the use of talismans, amulets, in short, the use of any object that confers security in situations of fear.
Thine own wickedness shall correct thee, and thy backslidings shall reprove thee: know therefore and see that it is an evil thing and bitter, that thou hast forsaken the LORD thy God, and that my fear is not in thee, saith the Lord GOD of hosts. Jeremiah 2:19
Idolatry can also be abstract.
Son of man, these men have set up their idols in their heart, and put the stumblingblock of their iniquity before their face: should I be enquired of at all by them? Ezequiel 14:3
A wicked conduct based on idolatry develops a codependency to people, to objects, to places, and even to situations. In general terms, idolatrous values generate a need for something, or someone.