In general, you have two options to host your Typo3 website. Either you choose a provider specialized in Typo3 hosting which also manages your Typo3 installation and updates, or you install the software on a general server/hosting package and take care for it on your own.
In the later case it is important to set the file permissions correctly. On one side, Typo3 needs some write permissions to do it’s work. On the other side you should make sure that no “bad guys” are able to enter your installation and produce any damages or inconvinience.
The following unix commands can be used to set valid file permissions for your typo3 installation if your server is managed with a plesk system.
The commands are specific to plesk managed system while names of the user groups and the httpdocs directory are typical for plesk servers.
It is assumed that the execution of the following commands is performaned in the base directory of your domain.
chgrp -Rf psacln httpdocs
chmod -Rf 755 httpdocs
chown -Rf <YOURUSERNAME> httpdocs
chgrp -R psaserv fileadmin typo3temp typo3conf uploads
chmod -R g+wX fileadmin typo3temp typo3conf uploads
Once again: note that the groupnames (psacln, psdaserv) are specific for the plesk system. If your manage your server with another software or do it completely on your own, you might need to use other user group names.