This paper addresses the problem of understanding sources of increased danger, identifying their types and essential characteristics. It substantiates the need to distinguish two groups of sources of increased danger: an object whose use during human activity creates an increased danger; and an activity that creates the potential for harm. The inappropriateness of using the characteristic of being beyond human control when defining sources of increased danger is demonstrated. The following general and specific characteristics of a source of increased danger are formulated: increased potential for harm; insufficient predictability of the outcome; and, in the context of Article 1079 of the Civil Code of the Russian Federation, the legality of the activity creating the risk of harm. Additionally, for objects whose use creates a danger to others, the following characteristics are identified: the presence of hazardous properties of the object and its involvement in human activity, where activity is understood as action and/or inaction; the ability/inability of a person to ensure the safe use of such an object. To compensate for damages within the context of Article 1079 of the Civil Code of the Russian Federation, it is necessary to establish the attribute of ownership.