APFS is Apple’s new file system, introduced in High Sierra. One of my favorite features of APFS is its partitioning mechanism. APFS volumes can be added and removed with ease to a container using Disk Utility. What’s fantastic is that there is no need to size APFS volumes. The volumes will grow and shrink automatically, as needed. This is incredibly useful if you have a new large drive and would like to use it for multiple purposes. For example, a drive can be used as a Time Machine backup, a bootable backup, and an application storage volume. With the traditional partitioning mechanism, you needed to put some thought into the sizing of each partition, as it can be difficult to resize partitions after the fact.
When creating APFS volumes, you have the option of setting a reserve size (minimum allocation) and/or a quota size (maximum limit). There does not appear to be a way to change these values after creating the volume.