In order for your website to be shown online, its files must be hosted somewhere. This is called hosting or web hosting.
Your server is the hardware on which your websites' files and data are stored. The server is also responsible for serving the website files when a user visits the website.
All websites require hosting from a reputable hosting company. Avoid finding the cheapest or even free hosting as they come with caveats that are not optimal for a professional or business owner.