Hello chuckbower,
Thank you for your question. On most servers (except some windows servers), all URL's are case-sensitive, the domain name section however is not, for example these will both work:
http://hawthornetechsvcs.com
&
HTTP://HAWTHORNETECHSVCS.COM
Everything following that is specifying a specific file or folder for example:
Services.html
I recommend using all lowercase in website file names, to make it more consistent.
If you have any further questions, feel free to post them below.
Thank you,
-John-Paul