Most programs and libraries are, by default, compiled with debugging symbols included (with gcc's -g option). This means that when debugging a program or library that was compiled with debugging information included, the debugger can provide not only memory addresses, but also the names of the routines and variables.
However, the inclusion of these debugging symbols enlarges a program or library significantly. The following is an example of the amount of space these symbols occupy:
a bash binary with debugging symbols: 1200 KB
a bash binary without debugging symbols: 480 KB
Glibc and GCC files (/lib and /usr/lib) with debugging symbols: 87 MB
Glibc and GCC files without debugging symbols: 16 MB
Sizes may vary depending on which compiler and C library were used, but when comparing programs with and without debugging symbols, the difference will usually be a factor between two and five.
Because most users will never use a debugger on their system software, a lot of disk space can be regained by removing these symbols. The next section shows how to strip all debugging symbols from the programs and libraries. Additional information on system optimization can be found at http://www.linuxfromscratch.org/hints/downloads/files/optimization.txt.