In our first article we discussed domain names. Buying a domain name gets you just that but it doesn't give you a web site or e-mail. To get that you need to rent Internet hosting.
Hosting is simply a computer that is on the Internet that can be accessed from the Internet. When you are using the Internet you are using a computer (PC, laptop, tablet, phone, etc) and connecting to other computers on the Internet (hosting). The hosted computers on the Internet run software such as web servers (for web sites) or email servers (for sending and receiving emails) or other useful things.
For hosting you just need a computer on the Internet that will do what you want. This seems simple enough but you need it to always be available (not crash/reboot) and fast (high speed Internet and a fast enough computer). This can be difficult to manage and expensive so there are different types of hosting to suit different needs:
Usually a hosting service will provide service to three basic needs: DNS, web hosting, and email.
You will already own a domain (eg. mycompany.com) but you will need you own domain server to use that. This domain server (DNS) will let you set up thing likes www.mydomain.com and mail.mydomain.com and point those at software that will manage it properly.
The web server will let you set up a web site that can be accessed over the Internet.
The email server manages sending and receiving of email for your domain. This is useful in that it looks more professional as you can use email accounts such as email@example.com instead of something like firstname.lastname@example.org.
Most hosting services also provide a database server which is used for storing data such as customers, sales, or whatever your business needs.
Virtual and real computers can be set up to do virtually anything.
You simply find one that suits your needs and rent it. Of course that is overly simplistic and needs further discussion. First examine the type of hosting you want. If you need virtual hosting you are hosting from the likes of AWS or Azure but if your are using that or actual computers you should know what your doing or hire someone that does. If you want application or shared hosting, make sure they are a price you want, have the services you need, and perform well at least in the locality (eg country) you want.