The influenza vaccine is unusual in that most years a different vaccine is made. Because strains of influenza virus that circulate in the community can differ from one season to the next, the vaccine must change to best protect against those different strains.
In VMware, switches are used to establish a connection between the virtual network and the physical network. With ESX and ESXi, two different kinds of switches can be used: standard switches and distributed switches.
Secure Digital memory cards are significantly smaller than CompactFlash cards, and are equipped with a nine-pin interface as compared to the 50-pin interface of the CompactFlash. The result of having fewer interface pins means that the SD cards are limited to a four-bit data bus, whereas CompactFlash cards have a 16-bit data transfer bus.