Linux Filesystem Hierarchy Standard
The /usr/local hierarchy is for use by the system administrator when installing software locally. It needs to be safe
from being overwritten when the system software is updated. It may be
used for programs and data that are shareable amongst a group of
hosts, but not found in /usr.
Locally installed software must be placed within /usr/local rather
than /usr unless it is being installed to replace or upgrade software
Structure is similar to
/usr, but is for site local software. Something you build yourself, or want to install an alternative version. configure scripts call this the prefix, often defaulting to the equivalent of
./configure --prefix=/usr/local. In contrast, distribution provided "system" packages tend to use
/usr. So by default, your custom-built
/usr/local/bin/vim will not be accidentally overwritten when the system package is upgraded.
As system administrator, you should understand how software is being installed, because your responsibilities likely include maintaining it. Query any package database for the files in question. Find out who's been running
make install from source.