Logical Volume Management: How PVs form VGs for LVs

When I set out to build my first system using Logical Volume Management I was surprised by the lack of information about how LVM relates to more "traditional" disk-level partitioning. There were plenty of articles with examples of how to use 'vgcreate' and 'lvresize' and no short supply of advice and white noise from the forums, but there was very little practical information about what the various strata of LVM were actually for or how they related to each other. In fact I was well into my search for information before I figured out where to put the file system.