The MAGE_RUN_TYPE parameter in Magento specifies the scope of the store switch that is being requested. There are two possible values for MAGE_RUN_TYPE: store and website.
When MAGE_RUN_TYPE is set to store, Magento will switch the current store view to a different store view within the same website. In this case, the MAGE_RUN_CODE parameter should be set to the code of the target store view.
When MAGE_RUN_TYPE is set to website, Magento will switch the current website to a different website. In this case, the MAGE_RUN_CODE parameter should be set to the code of the target website.
So the main difference between store and website is the scope of the switch. If you want to switch between store views within the same website, you should use store, and if you want to switch between different websites, you should use website.
Here’s an example to help illustrate the difference:
Suppose you have two websites set up in Magento, website1 and website2, each with two store views: storeview1 and storeview2. If you want to switch from storeview1 in website1 to storeview2 in website1, you should set MAGE_RUN_TYPE to store, and set MAGE_RUN_CODE to storeview2. If you want to switch from storeview1 in website1 to storeview1 in website2, you should set MAGE_RUN_TYPE to website, and set MAGE_RUN_CODE to website2.