Guided reading is small-group instruction where the teacher works with 4-6 students reading at a similar instructional level. It's not round-robin reading where students take turns reading aloud. It's not independent reading while the teacher sits nearby. It's intentional, teacher-led instruction at the students' cutting edge — the level where they can read with 90-94% accuracy with teacher support.
When done well, guided reading is the most powerful lever you have for accelerating reading development. It allows you to see exactly where each student is getting stuck and provide targeted instruction in the moment. The problem is it's often implemented poorly — rushed, infrequent, or without clear teaching points.