PEAR is a framework and repository for reusable PHP components. PEAR stands for PHP Extension and Application Repository. It contains all types of PHP code snippets and libraries. It also provides a command line interface to install “packages” automatically.
PHP is partially case sensitive. The variable names are case-sensitive but function names are not. If you define the function name in lowercase and call them in uppercase. User-defined functions are not case sensitive but the rest of the language is case-sensitive.