I am making a website and I just got to know something called MySQl. So- what is MySQL and what can it be used for??

hello- i m makeing a website but i don t know how to make a database for my website- for stuff like signing up and when people buy stuff like purchaseing membership.
i know the verry basics of mysql but it wasnt for a website it was fro a game. I don t know if that makes it any different- i also have used navicat because i didn t know how to change and navigate through msql that well.

i hav this weird issue- i ve never seen before. I have a search engine in my site and it works - i mean it finds results - only if i look for "icrosoft" instead of "Microsoft"- or "anasonic" instead of "panasonic"... what the problem could be?? i didnt set the mysql and the search engine was made almost by other guys...so i dont know where to put my hands on...

Ask: How can i change the root password to something else- the password who connects to the MySql- i dont want to change the mysql password.

I am a new php programmer -would any help me to Install php -run helloworld.php-and connect with MySql data base ?
what kind of softwares i need to install on my win xp OS. in order to run .php and mysql datebase connected programs.
thank you

I want to compile and execute .php files? for this i m using phptaid software? although i run some .php simple program i.e arrays -varialbe but i did not know how i would connect Mysql with Php files as i were using Phptaid software kindly anyone help me? would it necessary to install MySql and php if yes kindly give me link where i would easily download php and Mysql both software link which make me able to execute my php pages as below //localhost/example/filename.php