A similar issue as with the "-n" flag for netcat exists for "ls": Frequently "ls" is aliased by default in users home directories:
$ type ls
ls is aliased to `ls --color=auto'
On slow file systems (for instance, think of shared machines with large directories, NFS and heavy load) this can take ages to give output. Instead, if you just call /bin/ls, this call only calls http://man7.org/linux/man-pages/man3/readdir.3.html and thus gives output promptly.
I've seen \ls used to get the unaliased system version of ls. Likely useful for those commands where you don't want the aliased version and aren't sure if they live in /bin or /usr/bin.
Nice, didn't know about "\ls"! I wonder what's the difference between "\ls" and "command ls". Yes, it's a bit longer to type but the output is the same, I'm asking about what happens behind the scenes.
