There is the concept of Page in the InnoDB storage engine

When the system reads data from the disk to the memory, the basic unit is the disk block. The data in the same disk block will be read out at once, rather than what is needed.

The InnoDB storage engine has the concept of Page, which is the smallest unit of its disk management. The default size of each page in the InnoDB storage engine is 16KB. The page size can be set to 4K, 8K, 16K through the parameter innodb_page_size, and the page size can be viewed in MySQL through the following command:

mysql> show variables like 'innodb_page_size';

However, the storage space of a disk block in the system is often not so large, so every time InnoDB applies for disk space, there will be a number of consecutive disk blocks to reach the page size of 16KB. InnoDB uses pages as the basic unit when reading disk data to disk. When querying data, if each piece of data in a page can help locate the location of the data record, this will reduce the number of disk I/Os. Improve query efficiency.

Reference: https://blog.csdn.net/hao65103940/article/details/89032538