PHP is open source while SharePoint involves cost and it is really big enterprise solution.
SharePoint got web parts like MVC controllers while PHP got plugins.
SharePoint has lists/libraries as database while PHP got MYSQL.
List or libraries can manage permissions, large documents, they are easy to organize. you can separate different sites easily in SharePoint. you can have various authentication mechanisms in SharePoint like anonymous, Form based, windows based.
SharePoint got workflows where you can write any kind of business flow easily.
SharePoint got BCS to connect to other systems like SAP, Oracle. It got InfoPath forms where you can design complex LOB forms for end users. Creation of web application is very easy. SQL or FARM level replication is possible in SharePoint.
Nowadays, Office 365 is in much more demand offering lots of cloud based solutions and on various devices.
Regards,
Rupesh Singh
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