It supports wildcards and recursion into subfolders. It also supports the sending of username and password information where required.
It operates as a command-line utility and there are lots of optional parameters (which can be confusing to be quite honest).
In the past I have used it to invoke a function on a remote web server on a scheduled basis (if the function can be initiated using a HTTP GET or POST).
It's clever and powerful and it just works.
All the information (and links to download) are available here.
Here are some examples of usage:
# Download the title page of example.com to a file # named "index.html". wget http://www.example.com/
# Download the entire contents of example.com wget -r -l 0 http://www.example.com/