Traditionally, laptop computers were bought by people who had to be able to take their computer with them when they left the office, such as the salesman visiting a customer. It always used to be the case that buying portability meant a trade-off in terms of power and functionality, so desktop machines were the preferred option for those who didn't have to travel.
Is this still a genuine trade-off, however? It's time to re-examine the assumptions to see if they are still true.
Laptops are more expensive than desktops
While this is still true, the price differential is less than it once was, and may not be an overriding factor any longer. On the other hand, if you require a docking station, monitor, keyboard and mouse for use when you're in the office, the extra cost will be substantial.
Laptops have smaller, low definition screens
Once upon a time the laptop user had to be content with peering at a small screen, with poor resolution, and which was only visible when viewed straight on. Today's high resolution TFT displays are easily the equivalent of CRTs, to the extent that more and more desktop users are choosing them because they take up so little desk space. Furthermore, a 15" laptop screen has the equivalent real-estate of a 17" monitor.
Laptop users must struggle with small keyboards, and a joystick or touchpad instead of a mouse.
To some extent this is still true, although modern touchpad systems are so easy to use compared to those of a few years ago. With a docking station, you can use a full sized keyboard and a normal mouse when you are in the office, and get the best of both worlds.
Laptop memory and disk sizes are limited
While it's still true that laptops have smaller disks and memory than desktops, the incredible advance in miniaturisation means that even the smallest laptop has disk and memory much larger than the best equipped desktop of a few years ago. Unless you expect to store a lot of photographs, or do video editing, any laptop will have more than sufficient space.
It's hard to expand laptop hardware
This is still true, but paradoxically it doesn't matter! Once upon a time, adding a new device or peripheral often meant opening up your computer to install an expansion card. Nowadays, technologies such as USB and Firewire mean that all that is required is to plug your new device in. In this respect, desktops have lost their advantage.
Laptops are difficult to upgrade.
This is true. In order to pack a lot of power into a small space, manufacturers use proprietary hardware and custom connectors. If you expect to want to upgrade your disk, add extra memory, or even replace the motherboard, a desktop is still the best choice. Many users, however, would never do these things, so for them the distinction is unimportant.
Laptop data doesn't get backed up
Because laptops are typically taken home at night, they are not connected to the office network, so it is impossible for the IT department to include them in overnight backups. It is important that proper procedures are put in place to ensure that important data is replicated onto a server at regular intervals.
Laptops are easier to steal
Unfortunately this will always be true, a portable device, removed from the security of the office, is an easy target for thieves.
In conclusion, the distinction between desktop and laptop is still there, but it is not so important as it once was. If mobility and flexibility are important for you, it is no longer necessary to sacrifice functionality and ease of use.