To answer the switch part
A switch will manage IP traffic to improve performance, based on pre-loaded load balancing algorithms, for example if ports 2 and 5 are being heavily utilised the switch may prioritise IP traffic at the expense of the other ports on the switch (ok it's a bit more complicated than that but you get the idea)
A managed switch does the same, however via a web browser (or utility) you can manage the traffic prioritisation yourself if so desired, and many other features, but you would rarely use these in a domestic setup