What are some similarities between Mac OS X and Linux?
They are both Unix based.
The similarities are mainly what's under the hood. They are both POSIX compliant, both are based on UNIX conceptually (if not, in Linux's case, based on actual UNIX code), they use the same printer drivers (which Apple developed and shared), and OSX can even run most parts of the GNU/Linux toolchain; even X.org can run on a Mac. There are probably more that I haven't mentioned
Linux is a operating system, just like Windows and Mac OS. Unlike Windows and Mac OS Linux is free and open source. Some popular Linux distributions include, Fedora, Redhat, Ubuntu, Centos, and many more. If you would like to play around with linux try downloading a virtualization program and installing Linux on it.
Mac OS X is based on BSD, which is similar to Linux. Because of this, it is fairly easy to port programs between the two operating systems. However, the two operating systems are not the same, and programs for one don't work on the other. Linux also uses the X window system, and Mac doesn't, though Mac has a program to support programs that use the X window system. Because of this, Linux programs can…
I use a MAC. It uses UNIX for its operating system instead of MS DOS. A number of older computers used CP/M. Some computers use LINUX. In fact many nations or bureaus, education departments, states, or provinces require LINUX instead of MS DOS. LINUX has many similarities to UNIX and almost UNIX all programs will run on LINUX straight out of the box. A number of MS DOS programs will also run on LINUX.
Both Windows and Linux can be installed on an Intel Mac, so yes. If you were referring to binary compatibility with Mac OS X, Windows programs can be run using third-party programs like Wine or CrossOver Mac. Programs compiled on Linux are not binary-compatible, but most programs that are open-source and not specific to functionality in Linux can be and have been ported to Mac OS X. Most of these are available via Fink.
Boot Camp is designed to help people setting up Windows operating system under back as dual boot solutions. Running Linux under Mac is a bit more complicated, there are other solutions of Mac/Linux (dual boot) Mac/Windows/Linux (triple boot). Installing Linux on a Mac with other operating systems on board requires advanced knowledge (especially boot loader [rEFIt] and Linux kernel compiling).
It would depend on what you mean by networking. Macs play nicely with everyone. Linux/Unix somewhat and Windows not really at all. This is if you are looking at just simple network structure as in a home or small office. If you are looking at hosting bigger and over the internet I would look at going with Mac or Linux. I am a Mac guy fully because of all the pros it has over other…
If you download Linux on your Mac will it take over Mac OS and is there any way to avoid that without partitioning the HD if it does?
If you download Linux to your mac, nothing will happen until you initiate the installer. If you want to install Linux but keep Mac OS also installed, you will need to partition your hard drive. This can be done using the Disk Utility application that is found in the Utilities folder of Application. Finder > Applications > Utilities > Disk Utility