We mentioned earlier that there are two types of raster layers: tiled and untiled.

Before sharing ideas about tiling, the first thing to do is define tiling. According to Wikipedia, https://en.wikipedia.org/wiki/Tiled_rendering, it can be considered as the process of subdividing an image by regular grid.

So, why is this needed? Again, like for Closure Tools, it's for web performances. You can review about Closure tools in more detail in Appendix B, More details on Closure Tools and Code Optimization Techniques. Raster data and layers are built from other images or from vector data. The idea here with tiles is to balance the time for data processing and the time for transferring the resource (the image) through the network. It's also because using a regular tile grid can be cached, both by the browser and by the server.

Imagine that you require a complex layer. Would you want to wait for five minutes until it renders? (Rendering is the process to generate an image...