For any CMS it is very critical that it provide various ways for other application to interact with its repository at the same it should also secure its repository from the illegal access or intruders. Alfresco architects have always kept this point in mind and because of it Alfresco score much more in this area the other proprietary CMS competitors.
Alfresco gives you the choice to use either Web Scripts or the traditional, SOAP-based, Web Services.
Webscripts are very powerful services supported by Alfresco. Webscripts are RESTFul webservices which are bound to specific URI and responds to HTTP methods such as GET, POST, PUT and DELETE. The term REST had been introduced by Roy T. Fielding, one of the architects of the HTTP protocol. Webscripts can be invoked using that unique URL to which they are bound. They can be used as a replacement of typical SOAP based webservices. Webscripts has various advantages over webservices which makes them more popular among the developers and architects.
I will give you more details on how to create and use webscript in Alfresco in my upcoming articles so keep following my articles.