Wordpress is very popular and you likely have heard of it, especially if you have investigated options for builidng a website. Whether your needs are a Wordpress site or blog, or custom web application with Wordpress, I will point you in the right direction.
Before starting a project, you may wonder if this option is right for you. One answer can fit that comment, 'it is never the wrong option'. What this means is that Wordpress is a popular tool and can build practically anything and expand to almost anything.
But, let me explain why it may not be the best option. If you have minimal needs, like a simple small business website, a hand coded site can be built quicker(and cheaper) and perform faster. In addition, you could always add that blog later using a tool like PhpBlogifier.
Now, let's assume you need a web application. Wordpress has many useful plugins and the web developer can create new templates that allow custom coding. This will be a good option depending upon the sophistication of the site.
With Wordpress, you have the option to register users, add ecommerce features, assign admins and more. If you want some level of control over others, it is a valid option.
If you need an elaborate web application, the next step is often to use a PHP Framework, or make a realistic decision whether or not Wordpress would be adequate.
If the best option is to use a Framework, I would recommend a Framework I developed called SLAC. Having used several PHP Frameworks, I find it more flexible, faster to deploy applications, and faster performance.