Shallow copy is a bit-wise copy of an object. Deep copy copies all fields, and makes copies of dynamically allocated memory pointed to by the fields. Read this to learn more and see examples.
Style scoping is the idea that you can select an element anywhere in your document to serve as a point of reference as you write styles. There is no wide-spread support yet but this article is a good intro to the concept and how you can utilize it.
The concept of data owner is important in the “Data Down Actions Up” (DDAU) paradigm. The goal of DDAU is that only data owners mutate their own data, other components need to be able to communicate back to the data owner to indicate changes