If you want to use your own domain instead of *.tumblr.com, you can.

Tumblr requires very little technical knowledge in order to build and maintain a personal website.

Tumblr allow users to customize their website with many built-in themes. In addition to theme selection, users can also further customize their website either through a customization editor wizard or through a HTML and CSS editor for advanced users.

Tumblr supports responsive design for the website as it will be fitted with the same theme based on which device the user is using to view the website. It can also vary by theme with responsive design availability.