Storage Engine – Embedded code in an application that deals with the minutia of writing, sorting, and organising data so that out can be ent to storage devices in a fast and efficient way that facilitates its subsequent search and reading. This is about creating, reading, updating, and deleting (CRUD) data on physical disk and external disk arrays. When done effectively this creates significantic efficiency gains for the application by eliminating read, write and space amplification from compactions on an LSM-Tree, or inserts on writes for a B-Tree. An LSM-Tree is a data structure optimized for writes while a B-tree is better structured for reads. Example LSM Tree-based storage engines are the open-source LevelDB, RocksDB and Speed.