Dart was introduced on Google's official code blog by Lars Bak, a Google software engineer for the Dart team. Bak outlined three design goals of the new language in the post.
The first is to create a structured yet flexible language for web programming. Additionally the team wants Dart to feel familiar and natural, thus making it easier for programmers from another language to pick up on. Finally, Dart aims to be a high performance language that demonstrates its speed on all modern web browsers and environments.
One key element of Dart is the fact that it's an optionally typed language, making it a good alternative for small and large projects. For example, a one-person project would likely use dynamic typing which means they will add variables without defining their data type. For larger projects, it's a good idea to define data types to keep everyone on the same page. This is called static typing. With Dart, you can start with a dynamic typing project and later convert it to static.