What, "Keep font consistent means" in instructor comments.

 Word processors, like MS Word, Google docs, .pages, etc  allow writers to chose from different styles or appearances of text (called fonts), and also choose how big you want it (measured in "point").  

Only use on type of font in written work.  And keep the point size the same.  Don't use font or font size to add emphasis.  It attracts the wrong kind of  attention. I threw together a PDF to help demonstrate.