/lib is a symlink to /usr/lib. Most things should be using /usr/... in majority of cases. But the symlinks are there for backwards compatibility.
[label@xmpp01 ~]$ ll /
total 24
dr-xr-xr-x. 2 root root 6 May 16 2022 afs
lrwxrwxrwx. 1 root root 7 May 16 2022 bin -> usr/bin
dr-xr-xr-x. 5 root root 4096 Jan 26 15:33 boot
drwxr-xr-x. 20 root root 3360 Feb 2 22:12 dev
drwxr-xr-x. 97 root root 8192 Feb 2 22:12 etc
drwxr-xr-x. 5 root root 46 Jul 14 2022 home
lrwxrwxrwx. 1 root root 7 May 16 2022 lib -> usr/lib
lrwxrwxrwx. 1 root root 9 May 16 2022 lib64 -> usr/lib64
drwxr-xr-x. 2 root root 6 May 16 2022 media
drwxr-xr-x. 2 root root 6 May 16 2022 mnt
drwxr-xr-x. 4 root root 44 Jul 14 2022 opt
dr-xr-xr-x. 237 root root 0 Feb 2 22:11 proc
dr-xr-x---. 13 root root 4096 Feb 2 22:05 root
drwxr-xr-x. 31 root root 1020 Feb 2 22:13 run
lrwxrwxrwx. 1 root root 8 May 16 2022 sbin -> usr/sbin
drwxr-xr-x. 2 root root 6 May 16 2022 srv
dr-xr-xr-x. 13 root root 0 Feb 2 22:12 sys
drwxrwxrwt. 11 root root 4096 Feb 3 02:28 tmp
drwxr-xr-x. 12 root root 144 Jul 14 2022 usr
drwxr-xr-x. 19 root root 264 Jul 14 2022 var