Grouping of similar things together is called?

classification.

Classification

classifying

affinity mapping

Grouping of similar things together is called categorization or classification. When you categorize or classify things, you are organizing them into groups based on shared characteristics, features, or properties. This helps in making sense of complex information and facilitates better understanding and analysis of the items being categorized. The process of categorization often involves identifying common traits or patterns among the items and systematically sorting them into different groups or categories.

together with similar