PHP Basic -> Config

1. How to install php?
2. What are the default configuration likemax_file_uploads, max_execution_time, memory_limit, upload_max_filesize and upload_tmp_dir etc
3. From where to change the default configuration.? 
4. How to install new plugin/module in PHP?
5. Why we need to compile after installation new plugin?
6. Why we use ini_set and what we can do with this?

Following things keep in mind regarding this topic(Minimum)

• Default configuration of PHP varaibles.
• What is apache
• What is zend engine
• PEAR
• Apache Environment
• HTTP Headers Information
• Core modules
• New featurs in PHP5.3
• Deprecated function in PHP5.3