What is a bucket in a map physically?

In Go, a map is implemented as a hash table, where a bucket is a physical structure containing several elements with the same hash (collision). Each bucket is an array of fixed size (usually 8 slots), where key-value pairs are stored. When a collision occurs, elements are placed in the same bucket, and if the bucket overflows, additional buckets are created or reorganization occurs.

The bucket structure roughly contains:

• an array of keys
• an array of values
• a counter for the number of elements
• pointers to overflow buckets (if any)

This allows efficient searching and inserting of elements, minimizing the number of operations and maintaining performance.