What each piece of this command does: du /home | sort -nr +0 -1 | head -10

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I have the command:

du /home | sort -nr +0 -1 | head -10

and need to know what each piece ("du", "/home", "|", "sort", "-nr", "+0", "-1", "head", and "10") does.

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du /home 

du - Disk Usage

Command gives result of disk usage for /home directory in KB

| known as pipe; for feeding the output data to next command (sort)

sort -nr +0 -1

OPTION MEANING:

interpreting sorting keys alphabetically or numerically (-n option)

in ascending or descending order (-r -- sort in reverse option)

-n (numeric keys sorting)

+n (sorting using n-th field, counting from zero)

sort - sorting the result (see man pages for sort to find what those option does)

head -10

Finally it results the top 10 records

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du /home

gives a list of the "Disk Usage" (thus the name of the command) of every directory in /home and, recursively, all sub-directories. One line output per directory. "|" sends the output to the next command.

sort

Sorts the result, with "-n" specifying numeric (as opposed to lexicographic) sort, "r" specifies reverse order so the largest value appears first). "-nr" is equivalent to "-n -r"

head -10

Outputs only the first 10 lines of the previous command.

In essence it's finding the 10 largest directories in /home.

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du /home shows disk usage for every directory on the /home area of your disk.
sort -nr +0 -1 performs a reverse numeric sort on its input (which comes from the du command).
head -10 shows the first 10 lines of its input (which comes from the sort command).

man xxx shows you the manual for command xxx. For example, man du, man sort, and man head.