Caching, generally, is the strategy of creating easily accessible intermediate versions of assets. When retrieving an asset is expensive—in terms of time, processor cycles, memory, and so on—you should consider caching that asset. For example, if a list of Canadian provinces must be fetched from your database each time a person from that country visits, it is a good idea to store that list in a static format, obviating the expensive operation of running a database query on each visit. A good caching strategy is essential to any web-based application that serves large numbers of rendered data views, be they HTML pages or JSON structures. Cached content can be served cheaply and quickly.

Whenever you deploy content that doesn't change often, you most likely want to cache your files. Two general types of static assets are commonly seen. Assets such as a company logo, existing as-is in a content folder, will change very rarely. Other assets do change more often but much less...