Yes, using a switch allows you to connect more clients in your LAN. In addition, it limits the amount of traffic collisions in the LAN segment as well, allowing better performance and throughput of traffic.
For a small LAN network, a switch is best. To connect two or more LAN networks, a router is required. (2) From Jean Andrews CompTIA A+ sixth edition (page #852): You can use a crossover cable to connect to computers without a switch or hub making it the simplest network of all. For two or more you will need a switch, hub, or router.
Switch for small LAN, Router for two or more
a router or layer-3 switch.
Ethernet is a set of protocols to establish a LAN.
RJ-45 Black also known as the ethernet port
Connect each device to a centralized LAN switch using UTP cabling
An onboard LAN is a built-in ethernet adapter on mother board, if you have an onboard LAN, then, there is no need to install another ethernet card for your purpose.
It's called a switch. Many wireless routers have a 4-port switch. Also you can purchase a switch separately.
explain the ethernet lan layouts (10base2/10base5/any other)
LAN
It shouldn't matter which port you use unless it involves a network switch.
Ethernet