A student asked why ls /usr/bin/a* | wc issued from a user directory gave a different answer for the charcter count than ls a* | wc issued from within /usr/bin

Here are the first ten lines of the output of: ls /usr/bin/a* issued from within my home directory:

/usr/bin/a2p
/usr/bin/ab
/usr/bin/abrt-action-analyze-backtrace
/usr/bin/abrt-action-analyze-c
/usr/bin/abrt-action-analyze-ccpp-local
/usr/bin/abrt-action-analyze-core
/usr/bin/abrt-action-analyze-oops
/usr/bin/abrt-action-analyze-python
/usr/bin/abrt-action-analyze-vmcore
/usr/bin/abrt-action-analyze-vulnerability

Here are the first ten lines of the output of: ls -l /a* issued from within /usr/bin:

a2p
ab
abrt-action-analyze-backtrace
abrt-action-analyze-c
abrt-action-analyze-ccpp-local
abrt-action-analyze-core
abrt-action-analyze-oops
abrt-action-analyze-python
abrt-action-analyze-vmcore
abrt-action-analyze-vulnerability