Teacher account is for a single teacher to use independently.
$10 per month + three months free = $90 annual

School account is for all teachers plus administrators and more features.
$10 per student per year, $400 minimum

Teacher	School
		Gradebook
		Remote Learning, Online Assignments, Tests, Lessons
		Student/Parent Portal, Homework Organizer
		Messages & Discussion Forums
		Email Alerts
		Text Alerts
		Google Classroom, Google Drive, Dropbox
		Text-to-Speech
		Language Translation
		External Apps (LTI)
		Lockdown Browser for online tests
		Lesson Plans
		Seating Charts
		Co-Teachers
		Admin Access, Schoolwide Setup
		Import/Export
		Support by Email
		Support by Phone