What is the difference between yum, apt-get, rpm, ./configure && make install?

I am new to Linux and am running CentOS. I have come across four ways to update or install software.

So far, I've seen:

• yum install [program]
• apt-get install [program]
• rpm -i [program].rpm
• wget [program].tar.gz -> unpack -> ./configure -> make -> make install

That last one is a real pain, especially coming from Windows, where a program install is usually one click and a nice install wizard.

So, my questions are:

• Why are there so many different ways to do this in Linux?
• Which one do you recommend using, and why?
• Are there any other ways to install programs in Linux?

These tools all install software into your system, but are working on different levels.

• ./configure && make install

  Running ./configure && make install builds and installs the libraries or executables directly from the source code.

  The make install step basically just copies the final files into your system. Many sources come with a special make uninstall rule to remove them again, but this is not guaranteed and of course only works as long as you have the configured sources around. Also, this does not take care of required dependencies.

  Often there is only the source code available for a certain package, so this is the only way to go. Also, ./configure usually accepts lots of options allowing you to tailor your package.

  Not being able to find out what software installed which file, and the lack of a reliable way to remove them from the system are major shortcomings of this approach.

• RPM (Redhat Package Manager)

  rpm installs already configured and compiled software in your system and it also comes with a uninstall to get rid of it again. The packages have to be created by somebody. This person already decided on what features to include and how to best integrate the package into your system layout. It also comes with a list of dependencies.

  Since rpms are used for many distributions there, you will often want to make sure that this rpm was written for your distribution so that install paths, dependencies and other housekeeping things integrate well.

  On Debian systems, the equivalent package format is .deb and the installation and database is handled by the dpkg tool.

• Yum

  yum is an additional wrapper around rpm. It keeps its own database of rpm files available for your distribution, generally in online repositories. For the stable versions of most distributions all packages inside that database will play well with each other. This database can be searched (e.g. with yum search some_name).

  It will also automatically resolve dependencies for you. Packages (and with some extra help their dependencies) can be easily uninstalled as well.

  On Debian systems, the equivalent repository and dependency-resolution tools are provided by Apt (apt-get and aptitude).

So to sum it up: if you just want some software try yum first. If it is not available there, you can try to find an existing rpm package. If there is none or you have some special requirements, build from source.

Yum are RPM are the same thing except that yum gets the packages from the net automatically and installs them (using rpm -i) in one step. It should be used whenever possible to ease updating. Use rpm only when there is no package to be found by yum, and use the make method only when there is no .rpm package available or you need to change some compile-time options.