how to use your account or user in linux for webserver

usually when our ubuntu had installed a webserver,database and many more for web
mostly of user extract a that web or cms in directory /var/www
but now we can use an our public account for webserver
wanna know why is that could be happen'
and now,follow this way
1.go to your directory : cd /home/arofah
2.make direction : mkdir public_html
3.go to your directory : cd /public_html
4.extract your cms in public_html directory : unzip Joomla_1.5.11-Stable-Full_Package.zip
5.try this way in your terminal :
a. find /home/arofah/public_html/ -type d -exec chmod 755 {} \;
b. find /home/arofah/public_html/ -type f -exec chmod 644 {} \;
c. chown -R www-data:www-data public_html/
6.now check in your webrowser : http://localhost/~arofah/joomla
7.it's currently work in my lptop

note :
*d in type -d is change your user owner directory just root can create or delete and read in that directory
* f in type -f is change your user owner for file
*before you try this way,you have to log in root user