I observed that Following main Questions which are **frequently asked** usually tagged with [tag:apt] or [tag:software-installation] with [tag:command-line] or [tag:dependency]: - **Unable to locate package**: E: Unable to locate package [pkg] - **Package has no installation candidate**: E: Package '[pkg]' has no installation candidate - **Packages have unmet dependencies**: The following packages have unmet dependencies: package1 : Depends: package2 (>= x.y) but [pkg] is to be installed E: Unable to correct problems, you have held broken packages. Where `[pkg]` means package-name. ---------- From which we have already Questions as follows: - For Unmet dependencies: http://askubuntu.com/q/140246/256099 - For Unable to locate package I've prepared (which needs to improve): http://askubuntu.com/q/481354/256099 ---------- For new users of Ubuntu and command-line, further method of installing software properly, **It needs to prepare FAQ type wiki/solution on above (3) Main/Considerable Q/A.**