For Shopify & BigCommerce
Total Records = Number of Enabled Products + Categories + Pages + Blog Posts (across all stores
In cases where products have variations available, eg. size or colour, the variant products are indexed and counted separately towards the total number of records indexed.
For Magento & Other Platforms
Total Records = Number of Products + CMS pages + Category Pages (across all stores)
All enabled products with their visibility parameter set to Catalog, Search or Search Only are considered for indexing. In the case of configurable products, their associated products (even those individually invisible) are indexed and counted separately towards the total number of records indexed.
Note: Klevu maintains a separate index for each store view. Thus, if you have configured Klevu on 3 store views with 1000 records each, then altogether the count would be 3000.