Update index.rst

docs/index.rst

@@ -2,14 +2,15 @@ Welcome to ACHE's Documentation!
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 ACHE is a focused web crawler. It collects web pages that satisfy some specific criteria, e.g., pages that belong to a given domain or that contain a user-specified pattern.
-ACHE differs from generic crawlers in sense that it uses *page classifiers* to distinguish between relevant and irrelevant pages in a given domain. A page classifier can be from a simple regular expression (that matches every page that contains a specific word, for example), to a machine-learning based classification model.
-ACHE can also automatically learn how to prioritize links in order to efficiently locate relevant content while avoiding the retrieval of irrelevant content.
+ACHE differs from generic crawlers in sense that it uses *page classifiers* to distinguish between relevant and irrelevant pages in a given domain. A page classifier can be defined as a simple regular expression (e.g., that matches every page that contains a specific word) or a machine-learning-based classification model.
+ACHE  also automatically learns how to prioritize links in order to efficiently locate relevant content while avoiding the retrieval of irrelevant pages.
+While ACHE was originally designed to perform focused crawls, it also supports other crawling tasks, including crawling all pages in a given web site and crawling Dark Web sites (using the TOR protocol).
 
 ACHE supports many features, such as:
 
   * Regular crawling of a fixed list of web sites
   * Discovery and crawling of new relevant web sites through automatic link prioritization
-  * Configuration of different types of pages classifiers (machine-learning, regex, etc)
+  * Configuration of different types of pages classifiers (machine-learning, regex, etc.)
   * Continuous re-crawling of sitemaps to discover new pages
   * Indexing of crawled pages using Elasticsearch
   * Web interface for searching crawled pages in real-time