There are a number of desktops – some more popular than others. This page will go into detail of the different options, and what the benefits might be. Keep in mind that for educational or government roles, all desktop computers must meet the standards for PCs. All desktops will be allowed to have HDMI for connecting to monitors, and RJ45 for LAN connectivity.
The first are AiO (All in One) PCs. these machines are built into the monitor of the computer. With that being said, HDMI is not required for these types of computers. If the AiO is too thin, then the SD card reader must be built into the side of the AiO rather than the front.
micro/mini PCs are small computers with minimal capabilities. These are ideal for customer service centers, and locations where a lot of computers will have to be installed. micro PCs are usually cheaper, and therefore more cost effective for many businesses that don’t need high end machines. Keep in mind, to meet with NSC standards, micro/mini computers must have an SD card reader.
There are your horizontal computers. These are typically very rare as they have fallen out of favor for the smaller micro-PC, but for those that will benefit from a desktop, they will place the monitor on top of the PC itself. This is typically ideal in spaces where towers are too much space taken, and micro-PCs are not appropriate for the task.
Last, there are your towers. Towers can also be called vertical PCs since they stand tall rather than lying flat on a desk. These systems will typically sit on the floor. However, carpeted flooring is not advisable for such without an appropriate sized mat, or block to give the tower the air it needs to breathe. The carpet muffles such required airflow.