What is a Log File?
A log file is simply a file that is used keeps track of all that is happening with your site.
For example, it records:

• Each time a Web page is requested.
• What incoming link a visitor followed to arrive at your site.
• What search terms a visitor used at a search engine before arriving at your site?
• Errors that may have occurred.
• And much more.

Why Is Log File and Traffic Analysis Important
Analyzing your log file and traffic will give you insight into:

• How well your web site is performing
• How visitors are finding your site
• What pages are the most popular
• The geographic location of your visitors
• What search engines are visiting your site?
• How much of your site the search engines are crawling

Analyzing your log files will let you know how well your various marketing programs are working.

What Is Google's Page Rank?
Page Rank is part of Google's method of ranking web pages. Google explains it best at their web site:
"Page Rank relies on the uniquely democratic nature of the web by using its vast link structure as an indicator of an individual page's value. In essence, Google interprets a link from page A to page B as a vote, by page A, for page B. But, Google looks at more than the sheer volume of votes, or links a page receives; it also analyzes the page that casts the vote. Votes cast by pages that are themselves "important" weigh more heavily and help to make other pages "important.""
It is important to remember that Page Rank is but one factor Google uses to determine the rank of a web page in the search results. This is why you can find pages with a lower Page Rank listed above pages with a higher Page Rank. Google also factors in the content of the page and the pages linking to it.
Don't become overly concerned about your Page Rank. Focus instead on properly building a high quality site with loads of great content that serves your visitors well. If you do this, improved Page Rank will follow naturally.