slots come in three sizes: Type I, II and III. Type I cards are normally used for memory, Type II for input/output devices and Type III for mass storage and firewalls. 9. Go wireless Integrated wireless networking (Wi-Fi) has become an indispensable feature. Most notebooks ship with a variant of 802.11n these days, although some (such as netbooks) still use 802.11g. Public hotspots typically use 802.11g; fortunately, 802.11n is backwards compatible, along with 802.11b. Most mainstream laptops come with 2.4GHz 802.11n, whereas the premium ones come with both 2.4GHz and 5GHz. The difference: 2.4GHz has greater range, but lesser throughput. It also has more chance of interference, either from your neighbour's Wi-Fi or from other implements that use the 2.4GHz spectrum, like microwaves and cordless phones. 5GHz has less chance of interference and higher throughput, but has smaller range. Your wireless router will also need to support it for you to take advantage of it. 10. Power without the plug While you might have a two- or three-year warranty on your laptop, your battery is generally only covered for one year. Two specs to look for in laptop batteries are capacity (measured in milliamp hours, or mAh) and the number of cells. Typical batteries have an mAh rating of between 2000mAh and 6000mAh; higher is better. Cells are the actual compartments where power is produced, and can range from four to 12; the more the better. Keep in mind, though, that this may cause the battery pack to stick out