What is conservation of cultural heritage?

Wikipedia gives the following definition of conservation of cultural heritage:

Conservation-restoration, also referred to as conservation, is a profession devoted to the preservation of cultural heritage for the future. Conservation activities include examination, documentation, treatment, and preventive care. All of this work is supported by research and education.  The traditional definition of the role of the conservator involves the examination, conservation, and preservation of cultural heritage using “any methods that prove effective in keeping that property in as close to its original condition as possible for as long as possible. The conservator aims to take into account the views of the stakeholder and to apply their professional expertise accordingly.

Wikipedia divides conservation into two areas, these being:

Preventive conservation
Many cultural works are sensitive to environmental conditions such as temperature, humidity and exposure to light and ultraviolet light. They must be protected in a controlled environment where such variables are maintained within a range of damage-limiting levels. Shielding from sunlight of artifacts such as watercolour paintings for example is usually necessary to prevent fading
of pigments.

Interventive conservation
Interventive Conservation refers to any act by a conservator that involves a direct interaction between the conservator and the cultural material. These interventive treatments could involve cleaning, stabilizing, repair, or even replacement of parts of the original object. It is essential that the conservator should fully justify any such work. Complete documentation of the work; carried out before, during, and after the treatment rules out chances of later doubts.