Tony McCreath: All websites are in html. Php is a programing language you can use to dynamically create html.
Dave Elliott: it doesn't matter. If your favourite cms is written in php or aspx or whatever then that is the best language(other than tony's point above)
Kirk Fletcher: There are many languages you can learn to build/generate a website, each with their own strengths and weaknesses. Before thinking about PHP or the like I would recommend first learn how to build a solid HTML static website. maybe even start with HTML 5, this will give you the perfect grounding to start thinking about dynamically built sites (the kind using PHP will provide) absolutely the best place to start is but remember you will have to first get a solid grasp if HTML. Hope this helps :-)
Jaren Vitale: Thanks Kirk for solid make sense advice.