What does conserve/conservation mean?

When I took my first course in the field, the professor defined it as "wise use". You can make an entire philosophy out of those two words. In the more restrictive sense of wildlife conservation, it could mean anything from wiping out the species completely to growing the population as much as possible. In architecture, it usually is synonymous with preservation. With reference to pollution, it means rehabilitation. In other words,doing the best you can with what you have or "wise use".

To save jam in a jar.