How to host Sharepoint Site as internet site?

Hi,

Please guide me how to host a webapplication as internet site.We have SharePoint 2010 standard edition in which there already exist a web application(it has only one site collection and it has been hosted as internet site).Now I have created another web application and a site collection in that web application.I came across various terms such as host headers when creating a web application, alternate access mapping for a web application and site binding setting in IIS. One of my seniors told me there is no necessity for IIS site binding setting when we use alternate access mapping. Some sites instruct me not to go with alternate access mapping but give host header while creating the web application.

Thanks in advance.