All computers have ports. It would be pretty useless without them. Ports are just connections to the outside world. They are used to get information in to and out of a computer. Macs have plenty of ports and choosing the right port for the right is not as hard as you might think.
On its own, a computer is just a 'dumb' box. There are several extra components, or peripherals, that make up a computer system. A computer needs some sort of display to show what it is doing a monitor, and some sort of input device for us to tell it what to do a keyboard and mouse. Other devices that make up a system might include a printer, scanner, digital camera, speakers, or mobile device like an iPod/iPhone/MP3 player.
To go along with all these peripherals is another important piece of the puzzle, the Internet. A computer can connect to the Internet a few ways. The old and slow method is with a dial-up modem (no Macs have built-in modems anymore). The better way is through a high-speed connection like a cable modem or DSL line. The computer can connect to either of these by using an Ethernet cable a wired network, or with WiFi (aka 802.11a/b/g/n) a wireless network.
We will be looking at the ports on a Mac mini. These ports are pretty much identical to a MacBook, MacBook Pro (MBP), or the new iMac. Of course the big difference in these three models is that notebooks and iMacs have built-in displays, while the mini ships 'barebones' meaning no monitor, keyboard, or mouse. To use the mini you must connect it to some type of display.
The new mini has two ports for connecting to displays. The aluminum Mac mini now has a HDMI port, along with mini DisplayPort. This is currently the only Mac with a HDMI port. This makes it an ideal media center a popular use for the mini. HDMI is the standard port for HDTVs and increasingly on color LCD computer monitors. Both HDMI and mini DisplayPort are digital connections. Either port will work, however, DisplayPort is a bit more flexible since there are optional adapters to connect to several types of monitor inputs.
The mini does come with a video adapter in the box. It's an HDMI to DVI converter. Since most LCD monitors have DVI inputs, this does make sense and will work just fine. If you already have a monitor that uses VGA there is an optional mini DisplayPort to VGA adapter.
The latest Mac mini now has digital audio available on both the HDMI and mini DisplayPort. This makes it much easier to connect a mini into a home theatre system, a very popular use for the mini. There are also standard 1/8" audio mini jacks for both input and output. These jacks are also double duty since they are both analog and digital. To use the digital audio you need to buy special optical cables with the proper plugs on each end.
Ok, we've covered audio and video so it must be time for data input and output. There are two types of peripheral ports here. There is the very universal USB 2.0 port, of which there are four, and a single Firewire 800 port.
The great thing about USB is that it is cheap and most everything uses it. USB is used for keyboard, mouse, printers, scanners, memory card readers, cameras, etc. USB is relatively fast and robust. The only problem is that you can never have enough USB ports. The way USB works is one device or one port. The only way to get more USB ports is to use a hub. This multiplies a single USB port.
The USB port does have the ability to power a device. Your keyboard and mouse will pull power from the computer. A USB port can power some portable drives, hard drives or optical drives. USB can only carry so much power. If you plug in something that needs more power than the USB port can provide, it will not function. If you need extra ports it is best to buy a powered USB hub. This type of hub will have an A/C power adapter. The adapters power is then used to power any USB device instead of pulling power from the computers USB port. It is safer and more reliable.
Despite what you may have heard, Firewire is not dead. The main use for Firewire today is for external drives (hard drives and optical drives) and digital video camcorders. If you shoot digital video you want Firewire. If your camera uses memory cards, then it is not as important. Personally, I still like Firewire for hard drives and DVD burners. The data throughput on Firewire seems more reliable than USB, which is important for backup drives and DVD burners, which need a fast and steady stream of data for burning. Firewire is also used on higher end scanners and printers.
All Macs have wireless networking built-in. Wireless is convenient, but a wired network connection is more secure. Ethernet is faster and much more reliable. WiFi speeds are somewhere around 20mbs to 100mps. Since Macs all have Gigabit Ethernet we are talking speeds of almost 1000mps. A wired network is very important when you have several computers sharing music and video files, especially with HD video.
Ports are an important part of any computer. The more and varied ports a computer has the more flexible and expandable it is.