Secure Sockets Layer (SSL) provides secure connections by allowing two applications connecting over a network connection to authenticate the other's identity and by encrypting the data exchanged between the applications. A server identity is verified by three components: Private Key, Digital Certificate, and Trusted Certificate Authority.

htpasswd is used to create and update the flat files used to store usernames and passwords for basic authentication of HTTP users. Resources available from the Apache HTTP server can be restricted to just the users listed in the files created by htpasswd. This program can only manage usernames and passwords stored in a flat-file.

Setting up an e-commerce website is a little more involved than setting up a personal homepage. The basic domain and web hosting setup are identical, but the e-commerce website requires a few additional components to offer credit card processing and a secure checkout process. You may also use a 3rd-party hosted e-commerce application, but this article discusses the procedure for creating a standalone website built from a shopping cart application.

As described on URL Canonicalization article we published in March, having a unique URL for each webpage is important in improving your "Pagerank". Canonicalization is accomplished by redirecting non-standard web pages to a preferred ("standard") webpage. There are a number of ways to redirect a webpage, but 301 (HTTP/1.1 Status Code, "Moved Permanently") redirect is the search engine-friendly method that passes the PageRank and search engine ranking status from the old to a new page. Here is an example of how 301 redirects can be implemented in a LAMP (Linux/Apache/Mysql/PHP) environment.

One of the first things discussed when beginning an SEO project is URL canonicalization. You may argue that the impact of having multiple URLs resolving to the same page may not have a huge effect on SEO (if you use it consistently internally), but it certainly doesn't hurt to normalize the URL so that only one URL serves a single webpage. Implementation is not too difficult for most webmasters, and there is a piece of evidence that URL canonicalization will have a positive effect on your SEO effort. You may use one form (www or non-www) of Url for all your internal linking, but you cannot guarantee that others will do the same on 3rd-party websites.