Here's an example:
~$ ls /lib/*.so* | head -n 10
/lib/ld-2.13.so
/lib/ld-Linux.so.2
/lib/libacl.so
/lib/libacl.so.1
/lib/libacl.so.1.1.0
/lib/libanl-2.13.so
/lib/libanl.so.1
/lib/libattr.so
/lib/libattr.so.1
/lib/libattr.so.1.1.0
What do the numbers after so, such as in the last line, 1.1.0 mean?
My first guess was that they are version numbers, but:
~$ pacman -Qo /lib/libattr.so*
/lib/libattr.so is owned by attr 2.4.46-1
/lib/libattr.so.1 is owned by attr 2.4.46-1
/lib/libattr.so.1.1.0 is owned by attr 2.4.46-1
So the 1.1.0 does not seem to have any connection to the version of the library, reported to be 2.4.46.