To store a block in the system cache, the developer needs to set values for both the cache_lifetime and cache_key data properties of the block. The cache_lifetime property specifies how long the block should be cached, and the cache_key property specifies a unique identifier for the block.
The following code shows how to set the cache_lifetime and cache_key data properties of a block:
PHP
$block->setData('cache_lifetime', 600);
$block->setData('cache_key', 'my_custom_block');
Once the cache_lifetime and cache_key data properties have been set, the block will be stored in the system cache and will not be regenerated on each page load.