The significance of lesson plans in the context of education is that they are very important for ensuring that teachers teach the right things and do so in the right ways.  Planning is very important for good lessons.

If a teacher does not engage in lesson planning, their lessons will often be ad hoc and disjointed.  The teacher will not have a clear idea of what they are trying to accomplish with the lesson.  This will often lead to the teacher going off on tangents that are not related to what they really want to be teaching. 

If the teacher does not engage in lesson planning, they may not have good ideas about how to teach their lesson.  If they just go into the classroom and “wing it,” they might not have their students engage in a variety of tasks.  They might just do one thing throughout the whole class session, losing their students’ interest.

Overall, then, lesson plans are significant in the field of education because they allow teachers to do a better job of ensuring that they teach what they mean to teach and that they do so using a variety of techniques.  This allows for more effective lessons.