Setting up a network can seem daunting if you are uninitiated. There are three items that you see: IP address, subnet mask, and gateway. The IP address is the number of your machine. It will be something like 192.168.1.51.
The subnet mask tells you how many other IP addresses can be seen by your machine on your network. The standard subnet mask is 255.255.255.0. This means that your machine can see up to 253 other addresses on your network. You can see all the IP addresses from 192.168.1.1 to 192.168.1.254. If there is a machine set to 192.168.1.201 on your network with the same subnet mask you will be able to see each other. If there was a machine set to 192.168.2.5 on your network you would not be able to see it since it is outside of your range. To see it you would have to alter your subnet mask or go through a gateway.
A gateway is where information sent to addresses outside your local network is sent. Your computer checks against your IP and subnet mask and decides that the information needs to be sent outside of your network, so it sends it to the gateway. The gateway then forwards it onto the next network and eventually the information arrives at the appropriate IP address.
All these networks are linked together to form the Internet. There is only a limited amount of IPv4 address (3.7 billion) on the Internet, so IP masquerading was developed to allow multiple machines to connect through a single IP. These masqueraded networks generally use private address space IP addresses to share the single IP address that you are given by your (Internet Service Provider) ISP to connect to the Internet. The 192.168.x.x is one of these private ranges and if an IP from that range appears on the Internet, it will be ignored. This way your computers, phones, tablets, printers, and other devices can all connect through the single IP address your ISP provides you.
This knowledge can be very helpful when your computer cannot see your tablet. You can verify that both should be able to see each other. Often the issue is that one of the devices is not getting a proper IP address.