What does Loading time mean?
Loading time describes how quickly a website makes its content available. User experience and measurements depend, among other things, on the server, files, network and device.
AN EXAMPLE IN PRACTICE
Where you might encounter it
For smartphones, your website loads a smaller image file than it does on a large desktop screen. This saves data transfer without serving the same large image to both devices.
From NetzTurm Decode. Clear explanations with historical context.