Target audience: Textbook: student / Lesson plan: teacher
Type of activity it guides: Textbook: Solitary / Lesson plan: Group
Scope: Textbook: Subject / Lesson plan: Single lesson
Objective: Textbook: Comprehensive set of explanations for a broad subject / Lesson plan: Tactics for a teacher to facilitate learning
I'm not a teacher, and it has been many years since I was at school, but I see little commonality between a textbook and a lesson plan.