You can think of it like a rubber band: more elastic means it moves more. Elastic demand is more likely to be affected by circumstances. For example, demand for many luxury items is fairly elastic for non-wealthy people because if they lose their jobs, the economy goes into recession, etc., they tend to stop buying the luxury stuff. On the other hand, inelastic demand is a lot less dependent on outside factors. So, even if you lose your job, the economy fails and there is a massive earthquake, you're still going to need to buy bread, salt, etc.
