What is APACHE WEB SERVER?

what is apache web server is it like a server where I upload my website or its something else. for up loading a website do I need a Hosting company or can I use Apache web server aby way I need some info on this please
Also what is joomla

When you put in a webpage address, your browser navigates to a server. That server is a computer, but in order to send and process the request it requires software. This software is called a Web Server or more precisely an HTTP Server. There are lots of different brands, just like operating systems. Apache is one of the oldest and most reliable. It can be run on Linux, Unix, and Windows. A hosting company may be using Apache. Yes you would your html files and images into certain folders so the web server would know what to send for a requested page.

Joomla is a content management system. It is a bit harder to explain, if you don't understand web servers. Think of it, as an easier way to build large sites faster and make them easier to manage.

Apache Web Server is a software application that many Internet Web Hosts use. It handles HTTP requests over the internet ususally providing web pages (HTML Documents) to the requesting client, usually a browser like Firefox, Opera or Internet Explorer. It can handle many requests at a time. You can use it on a private network or a single computer to send HTML pages to browser. You usually need a hosting company to serve your WebSite.