At the heart of a content management system is the database. This is where your actual content is stored. Your content can be text, images, pdfs, audio and video files, and so forth. This content can be reused anywhere in the website. The other part of the CMS is the design template. How do all of this come together to save you time and money?
A website created by a content management system is dynamic because each page is created as soon as the user clicks on the link to view the page. You do not hard-code the pages ahead of time and have them just sitting there waiting to be clicked on. When a user clicks on a link to a page, the internal coding of the CMS calls in all the parts that make up the page, brings them together, and renders the page on the browser to display it perfectly to the user. All of this happens almost instantaneously. If you happen to need to change something on the menu bar, for example, this change does not have to be manually made on every page because there are no hard-coded pages sitting around. The change just has to be done in one place, which is the menu bar element. You make one change, and this change is effective on every page that requires the menu bar. The next time one of those page is clicked on, the new menu bar will be displayed.
If this website was a static website, this change on the menu bar will have to be made on every web page. Think of how time-consuming that would be. If your website has 100 pages, that is 100 menu bars that you have to edit. If you are paying someone to maintain your website, that can translate to more time that you have pay for.
You can even use multiple templates on your website. All of your web pages do not have to look the same. Sometimes you want to dress up certain web pages just to add interest for your potential customers. Perhaps one page, you want to add a module with a news feed. Or, you want to insert a mini feedback form on several pages. With CMS, you can pick and choose the type of modules that you want to add in. It all depends on what your CMS platform offers you.
You may want to use a different design template for different seasons. For merchants who often have seasonal promotions, being able to change the design of the pages easily to suit the season enables them to attract more customers. It is similar to window dressing for the brick and mortar stores. If the window dressing looks interesting, customers are more likely to go into the store to browse and purchase.
With a click of a button, you can give your page a whole new look. The content stays the same. You are merely choosing a different way to dress it up. Again, with a static HTML website, you would need to spend hours editing the style sheet to give your web pages a new look. With CMS, this can be done seamlessly and painlessly.