83 URLs submitted in Sitemap but only 1 Indexed

[cssatsc]

My recent check of Google Webmaster tools reveals that 83 URLs were submitted in the XML sitemap but only 1 of them was indexed.

Need I worry?

I mean, what does "lack of indexing" mean? Is it Google's famous "penalty" or simply a natural result of lack of backlinks?

There are no crawl (or any other) errors, and all of my site's URLs are being found on Google search (albeit not highly ranking).

What does "Indexed URLs" really mean?

Thanks.

[tedster]

all of my site's URLs are being found on Google search

That's the only kind of "indexing" that matters. The Webmaster Tools reports get buggy, and the site: operator results are seriously buggy. But if a URL shows up in the search results with a title and a snippet, then it is indexed.