Practicality: It requires minimum  knowledge of programming.Power: It has the ability to interface with databases, form and create pages dynamically.Possibility: Developers are rarely bound to any single implementation solution.Price: It is open source software.

PHP implements the MD5 hash algorithm using the md5() function,
eg : $encrypted_text = md5 ('password');

The enctype attribute determines how the form-data should be encoded when submitting it to the server. We need to set enctype as "multipart/form-data" when we are using a form for uploading files

Thare are two functions are used to add file in a script
1.The include()function
2.The require() function

passing arguments by value:Means any changes made to those values within the scope of the function are ignored outside of the function.
passing arguments by reference:Means any changes made to those values within the scope of the function are reflected outside of the function.