is my iOS application is a Web Application?

I'm developing an iOS application that communicates with my server.

Above picture shows how my iOS works.

I want to know whether my iOS application is an Web Application or not and what is Web Application exactly.

I read below web site. http://ift.tt/2i7njuW

However the definition of Web Application is too ambiguous to me. It seems that usually web browsers are needed for Web Application to perform tasks. However my iOS application doesn't need web browsers(chrome, safari etc..) to perform tasks and my iOS application is essential to perform tasks.

I have some questions.

1.In this case, is my iOS application(including php Server and db) a Web Application? 2.Or.. is my php Server including db a Web Application? 3.Is my iOS application a web browser?(My application is quite different from web browsers such as Chrome and Safari. It only communicates with my php server and it doesn't show web page. My app just ueses json http response from server to perform tasks)

Thank you in advance :-)