https://it-jerryfamily.tistory.com/entry/lazy-loading과-eager-loading-의-차이점
https://www.imperva.com/learn/performance/lazy-loading/
https://stackoverflow.com/questions/31366236/lazy-loading-vs-eager-loading
Lazy loading is the practice of delaying load or initialization of resources or objects until they’re actually needed to improve performance and save system resources. For example, if a web page has an image that the user has to scroll down to see, you can display a placeholder and lazy load the full image only when the user arrives to its location.
Eager loading also involves pre-loading related entities referenced by a resource. For example, a PHP script with an include statement performs eager loading—as soon as it executes, eager loading pulls in and loads the included resources.
Eager loading is beneficial when there is an opportunity or need to load resources in the background. For example, some websites display a “loading” screen and eagerly load all the resources required for the web application to run.
When to use eager loading
When to use lazy loading
Note: like Transcendent said there may be disposal problem with lazy loading.