What a CMS is, and why a site needs one

A CMS (content management system) is software for editing a site’s content without knowing HTML: an admin screen, storage, templates, roles and publishing.

A site you have to edit every week

A site of HTML files is fine until it needs editing. But an owner changes prices, adds services, writes news. The site has fifty pages, and the header is copied onto each. The phone number changes, so we open fifty files. A service’s price is written on its own page, on the home page and in the price list: forget one, and the site shows two prices. And the person who changes the prices doesn’t have to know HTML. That’s how the need for a CMS arose.

Three layers

Every site is made of three layers, and how they are separated decides everything that follows. Move the slider in the diagram: at its three stages you can see where each layer lives and what it takes to change the price of one service.

How the site is built: A site of HTML files

Files on disk

Contenttext and prices right in the HTML

Templatethe header and footer copied into every file

Codenone: everything is ready-made

Database and admin screen

nothing yet

Who can change it: Whoever can edit HTML and upload files by FTP: usually a developer.

Changing the price of the first service:

1. Find every page that mentions the price of the first service
2. Open each one and fix it by hand
3. Upload the fixed files to the server

What can go wrong: One page is forgotten, and the site shows two prices.

Text alternative: in a site of HTML files all three layers (content, template, code) live in files, and the price has to be edited on every page. In a CMS with pages the content has moved into the database, but the price is still buried inside text. In a CMS with a content model the price is a field of a record, and one edit updates it everywhere.

• Content: text, prices, photos, names, the reason people come.
• Template: how the content looks and where it stands. The shared header and footer, the look of a service card.
• Code: what the site does. Find the right record, show a page, take a request, check who has logged in.

In a site of files all three layers are mixed in one HTML. In a CMS they are separate: the content lives in a database and is edited in an admin screen, there’s one template for all pages, and the code is written once.

What a CMS is

A CMS (content management system) is a program that lets people who don’t know HTML edit a site’s content. It usually includes:

• an admin screen: a page for editing, behind a login;
• storage for the content (most often a database, as in part 7, though it can be a set of files);
• templates: the design, written once;
• roles: the owner sees everything, an editor changes the text but not the settings;
• a media library for images and files;
• versions and publishing: a draft, a preview, a way back.

A CMS site is a dynamic site in the sense of part 6: a page is put together on request from the content in the database and a template (or in advance, as in the lesson on generators, but that comes later). There are very many CMSs, and in part 8 we’ll go through the main kinds: WordPress, website builders such as Wix, Squarespace and Shopify, static site generators and “headless” CMSs.

The content model

The heart of any CMS is the content model: a description of the kinds of “things” there are and what they have. Each kind of “thing” is a type, and what it has is its fields.

Type	Fields	Who edits
Service	name, description, price, photo	owner
Person	name, job title, biography, photo	owner
Proof	name, number, date, scan	editor

A principle worth remembering: model the content, not the pages. Not “the page about the boundary survey”, but a “service” with fields. Then one record is shown in several places: a card on the home page, a page of its own, a list in a section, later a line in the search results. Change a field and everything changes. Structured content is also something search engines and AI can understand (part 13 comes back to this).

What goes into a field’s description:

• the data type: a string, long text, a number, a date, an image, yes/no, or a link to a record of another type (a service has a “lead specialist”);
• whether it’s required: may the field be left empty;
• languages: if the site has several, the field is repeated for each (title_en, title_es), or a translation of the record is made and linked to the original.

A mistake everyone makes: pouring everything into one “Text” field with an editor where people format as they please. A year later it holds the price, the terms and the phone number, and nothing can be found or reused. A price should be a field.

Check yourself: why is it better to make the price a separate field than part of the text?

From a separate field it can be shown in the card, on the page, in a list and in the markup for search engines, and it has to be changed only once. A price hidden in text has to be found and fixed by eye in every place.

Who edits, and how often

The choice of a CMS is almost entirely decided by two questions. Who edits the content: an owner with no technical knowledge, an editor, a developer? And how often: every day, once a month, once a year? If the site is edited twice a year and by a developer, a CMS may be more than you need: files are enough. If several people write news every day, you can’t do without one. You’ll write down both answers for your types right in the practice.

Practice

You’re in the era of 2010: sites on a CMS are no longer rare, and owners of small businesses edit them themselves for the first time. Start with the content model.

The page has a table of content types. The first row (services or products) is almost done. Fill in the others: people, proofs, section pages (or types of your own), with the fields of each and who edits it and how often. In the second table, for each section of your site, say which content types it shows.

What was wrong before

Sites of the 2000s began as files, and the shared header was pulled in with “includes” (server-side includes, Dreamweaver templates). That was a first step toward separating the layers, but editing still took a webmaster: every change cost money and waited for weeks. A CMS put editing into the owners’ hands. The price was different: the site became a program that has to be updated and protected (lesson 3 is about that).