Most websites now are built with some sort of content management system attached to them. This system will usually allow the end user to make some changes to the website often without having to know or understand any code.
There are a number of off the shelf content management systems you can use on a website or some programmers will have designed and built their own. There are pros and cons to both as off the shelf ones often tend to be a bit easier to use and are very easily and regularly updates but bespoke ones can add in functionality you may struggle to find with an off the shelf CMS. This may also mean that the website can cost less money than if a programmer has to try and change an off the shelf content management system to integrate the functionality you need.
If you are using an off the shelf CMS then you may find it easier to move to another website programmer if you need to in the future. Programmers who have designed their own CMS system tend to only give you the front end files of the site and you would need to pay for someone to adapt it to another content management system so it works.