Web Client

How many computers do I need to install in order to access the web client?
In my case, I installed the SQL Server and Nav Server in one machine and client in another machine. In order to access the applicatoin from web browser, I need to install portal sharepoint. Here is my question. Can I install the portal in the machine where SQL server and NAV server installed? Or do I need to install SQL Server in one machine, NAV Server and Portal in one machine and Client in the another machine, the total of three computers? Thank you!