What I mean is so called evergreen content, which is simply ageless and is more valuable than trendy news. If you start blogging about history it won't change so the content doesn't get old but if you write about the new iPhone 5S and when the new iPhone goes out your post is outdated and doesn't offer much of a value to your readers.

This guide you are reading now is an evergreen content because these points will be valid in a year, two or a decade. Some of the points will be irrelevant or outdated but the main idea and process will stay very similar.