In vuejs there is the vue created lifecycle hook method that can be used to define some logic that should run after the vue instance is created, but before the vue is mounted to a mount point in html via the vue el option or the mount instance method. This is one of many hook methods that can be used when creating a vue instance to define some logic that will happen at the various statges of the vue instance lifecycle.
For a basic example of the vue created lifecycle hook here is a quick example that logs the value of a vue data object property, and the current value of the $el property as well. The vue created hook fires after the vue instance is created, so the value in the data object is present at this time. However the value of $el is undefined because the vue instance has not yet been mounted to the html document mount point selected via the vue el option, or the $mount instance method.
The vue created hook is called synchronously so anything that might envolve heavy listing that is not delayed some how will delay the lifecycle from preceding to the mount hook.
If the vue el option is not used when creating the vue instance then the lifecyle process will come to a halt after the created hook until the $mount method is used to mount the instance to a mount point in the html document.