This article lists out some very important google classroom terminologies that are often used, as sometimes users are confused about their navigation. Screenshots are also provided for easier navigation.

Class Name: While creating a class you must provide a Class Name like Grade 6 or Grade 7, etc.

Class Section: Its sub-category of Class. It is not required. 

Class code: A code to join the class. Teachers will see the code whenever they will create a new class. They can also see the already created Class Code from the class settings icon that appears in the top right corner.

Setting icon in the top-right corner

After clicking the setting button of class, you will see this information in the popup.

CLASS LINK: The class link is used to join the class. You can find it in the same ways as Class Code.

Select theme: Teachers can select a theme (color or images) for the class that will be applied to all students.

Stream: It's a tab on Class where teacher and all students in the class can see what's going on. The assignments, Quizzes, Announcements, etc everything appears there.

People: People tab is visible to all, where teacher and students can see the other student and teacher. People tab shows their image, name, and email.

Assignments: A test or task that the teacher assigns to the student. It can be customized, as explained below.

After selecting the type of assignment, details, points, and due date can be set

Grades: It's a Tab in teachers' accounts where they can see the submission of quizzes or assignments of students and assign them grades accordingly.

Announcements: Teachers can make announcements in the stream tab, and all students can see them. Announcements can be made for single or multiple classes at once.

Make it specific to all single or all classes.

Classwork: It's a tab that shows the quizzes, assignments assigned to students.

Turned in: It shows how many students have submitted the assignment. Teachers can find it in different places like in the Classwork tab, click any quiz or assignment, you will see the Turned in.

Turned in late: When a student submits an assignment late, the Teacher will get email about Turned in late. But now it’s renamed to Submitted Late. See below screenshot.

Submitted Late | Google Classroom terminologies
The teacher got an email with Subject Submitted Late.

And teachers can also find it under Grades Tab. it is labeled as Done Late.

Your work: In the student’s account It is work (in the format of files) that students submit in answer to an assignment. See the below screenshot.

Class Comments: It is the common general discussion in the form of comments that teachers and students can find in the Stream Tab.

Teachers can find it in the following way:
Click any quiz in the Stream Tab.

Then click on the Instruction tab.

Students can find it in the following way.
Click on any quiz in the stream tab. There you will find the comments/discussion.

Private comments: It's a student-side feature. Students can talk to the teacher privately. Click on any quiz in Stream Tab, and there you will find it on the right side

Returned submission: It is a feature for teachers. It is used to reject a student submission. Go to Grades Tab. Click the three dots on the submitted assignment. And click the View Submission option to see the details of the submission. Or you can click the Return option to reject the submission. 

Invite Guardians: Teachers can invite individual students’ guardians and let them know about the performance of their students. You can find it by clicking on the People Tab and seeing the option of inviting guardians right before the students provide a pic. Teachers can invite them for one or all classes they teach to that teach.