A部分

warSourceDirectory是静态Web文件，jsp，图像，WEB-INF等的目录.默认值为好"，因此您无需更改此参数.

webXml-是 web.xml 文件(部署说明)的位置.使用Spring Boot，您根本不需要web.xml.将参数 failOnMissingWebXml 设置为false. /p>

B部分

项目内部定义的插件始终由该项目使用.仅在启用配置文件时才使用配置文件中定义的插件-因此该插件不是默认插件.

Can anyone please explain the functionality for below?

A) Actually below code is working for me, BUT I didnt understood why we need to use below for maven-war-plugin

<warSourceDirectory>src/main/webapp</warSourceDirectory>
                    <webXml>src/main/webapp/WEB-INF/web.xml</webXml>

B) whats the difference between keeping a plugin inside a project and inside a profile? ( say maven-surefire-plugin ) which way is better (assume I MUST use <profile> tag in my pom.xml)

Part A

warSourceDirectory is directory for static web files, jsp, images, WEB-INF etc. The default value is good, so you dont need to change this parameter.

webXml - is location of web.xml file, deployment description. With spring boot you dont need web.xml at all. Set parameter failOnMissingWebXml to false.

Part B

Plugin defined inside a project are used by this project always. Plugin defined in profile are used only when you enable profile - so this plugin is not default.