Assessment is educational evaluation, the systematic way of collecting information and reading the work of class which is used to guide and improve student's performance in terms of learning and development. There are several methods that teachers use to evaluate the learning progress and skills of students or the need for any academic assistance. It actually determines whether or not the goals of education are met.

Summative Assessment (Assessment of Learning):

• It is also known as Assessment OF Learning is to evaluate student learning by comparing it against some standard or level.
• The main objective is to rank, grade, classify and compare students periodically that indicate their level of performance.
• It is considered a Formal method of Assessment as it is conducted at a specific time.
• Example: Mid-term Exams, unit tests, final projects, semester exams, etc.

Formative Assessment (Assessment for Learning) :

• It is also known as Assessment for Learning, used to evaluate student learning progress and achievement.
• The goal is to collect detailed information like strengths, weaknesses, knowledge, skills, etc., and then plan the next lesson in a way to improve the performance of the students.
• It helps teachers to identify problem-facing areas, to understand and learning needs for achieving academic growth. 
• It is considered an Informal Method of assessment as it can be conducted at any time or during teaching also.
• Example: Discussions, Class tests, homework, assignments, debate, plays, etc.

Assessment as Learning

• When learners are asked to assess their performance on their own, they use various assessment techniques and strategies to assess themselves.
• This practice helps learners to identify their knowledge gaps, adopt appropriate learning strategy and use assessment as a tool for new learning.
• It encourages students to take responsibility for their own learning.
• It requires students to ask questions about their learning.
• It involves teachers and students creating learning goals to encourage growth and development.
• It provides ways for students to use formal and informal feedback and self-assessment to help them understand the next steps in learning.
• It encourages peer assessment, self-assessment, and reflection

So, If a teacher collects and reads the work of the class, then plans and adjusts the next lesson to meet student needs. He/She is doing Assessment for Learning (Formative Assessment).