Rank
Definition
How much information a matrix really holds. The number of linearly independent columns.
Notes
This is a bulk of Caitlin’s doctoral work. I’m not quite the specifics, but when I went to all her talks. It’s a lot of full-rank this, full-rank that.
Full rank
The rank of the matrix is the same size as the smallest dimension
From solving a linear system point of view, when the square matrix is rank deficient, it means that we do not have complete information about the system, ergo we cannot solve the system.