You will very likely have a dynamic ip. This is an address that changes with time. In order for other to connect to you, even directly over your home network, you will have to have this address. Local to your own machine, local network, as well as over the internet. Static IPs are far more simple and easier to create networks from, as well as to set up hosting --- they are more expensive to purchase since they have a history of use in business networks, go figure.
If you are connecting over the internet itself, chances are that you are provided an ip as well as has a few ports closed for security (or profitability). You can find that out from your ISP. (Internet Service Provider - not insulting just vocabulary)
If you are connecting through a router, then you will find that you have port forwarding to attend to on the router. This will take the request (http) and send it to the right machine on your network.
You may find that your router actually sets your machine to a different IP address then you had expected. This is because it acts as an IP server within your network.
Over the internet, it is your ISP that acts as your IP server so it knows where to send the content that you request when surfing. This is where the ip checkup in the earlier post comes in. This will provide either the IP that your ISP provides for your machine if connecting directly, or for your router.
Be careful when using public networks such as internet service provided through a school or at a cafe. Sometimes these services don't provide all that is needed for other to reach you, at all. Instead, you will receive their IP address for routing content, but requests for content will only go to them.
--- the base domain of the link provided in an earlier post --- carries a number of services for dynamic ips, such as a name server offering. You can create an account that uses more common names instead of numbers. The names that you enter into your web browser when you visit a website are surrogates for an IP address.
You can use the check IP service to provide your IP in a numerical form to give to others, you can also use their services to provide a name to others. This is also helpful as any changes to your IP are updated to account on their nameservers and those will also point to you. It also makes it a great deal easier for others to connect to you.
You may even find that if your router may have features built into it that allow it to update an account with http://www.dyndns.com
, or you may need an application such as DirectUpdate (DynDNS has a list of these - free and paid) to do just the same thing. Both options are quite straightforward to complete once you have some orientation in the subject. This comes with time and simplifies the issues in the long run, easing the kind of frustration inhibits learning.
Google "DHCP", "TCP/IP", "Static IP", "Dynamic IP", "Router", and "Name Server" for a lot of help in this matter. (DHCP stands for Dynamic Host Configuration Protocol TCP/IP stands for Transmission Control Protocol/Internet Protocol all needed vocabulary.)