A graphic designer is a professional within the graphic design and graphic arts industry who assembles together images, typography, or motion graphics to create a piece of perfection, which is still not perfect in the most beautiful way ;)
PHP developers develop programs, applications, and web sites using the dynamic scripting language PHP. PHP is known for web development and business applications.
Software Testers are responsible for the quality of software development and deployment.
A web developer is a programmer who specializes in, or is specifically engaged in, the development of World Wide Web applications, or applications that are run over HTTP : CSS OR HTML