I assume that you are talking about a desktop PC rather than a laptop or tablet. Some modern motherboards include a wireless adapter to allow for WiFi connection. Almost all modern motherboards include an Ethernet adapter capable of providing a 100 Mbps connection. Some of these will support 1000 Mbps (1 Gbps). If the motherboard does not have integrated WiFi capability, then there are three common solutions. In order of popularity (most popular first) these are: 1) A USB wireless adapter. All motherboards now include USB2 capability as standard (some provide USB3). A USB wireless adapter can be plugged into a spare USB port. This does not require the PC to be opened. There are various types, some with fairly sophisticated antennae, while others look more like a USB memory stick with the antenna hidden inside. The smaller adapters tend to be less sensitive, but are normally fine if you are within about 5 metres of the router and in the same room. 2) An adapter card fitted inside the computer. You have to make sure there is sufficient space on the connector panel at the back of the PC to allow the card's external connectors to be mounted correctly. Also, there has to be a suitable socket on the motherboard to match the connector that the adapter uses. For both the two options above, you must make sure that the network adapter comes with the appropriate Windows 10 drivers, which will have to be installed for correct operation. Both these options as well as using WiFi that is integrated into the motherboard will require one or more antennae outside the computer's metal case so that they can connect properly to the WiFi signal. Laptops and tablets get round this by have plastic cases that allow the signals to pass through. 3) Use an external WiFi to Ethernet adapter. This requires no additional drivers assuming that the motherboard has working Ethernet. Unlike a wireless adapter, Windows 10 will frequently have the appropriate Ethernet drivers already installed. This option is also a good way of connecting devices such as Internet ready TVs that have Ethernet but not WiFi. However, assuming the PC has Ethernet, it is a desktop (non-portable) PC and there is no problem running a cable back to the router, then Ethernet should always be the option to use. Unlike WiFi, which is a half duplex channel shared between all the devices connected to the WiFi network, Ethernet provides a dedicated full duplex link over the Ethernet cable. This can be very important if you intend to play online games. I hope this helps.