Explain the difference between the four Data Mapper types and how you choose between them.

The four types divide along two axes: read versus write, and simple versus flexible.

1. Turbo Extract — reads one sObject, no formulas, minimal restructuring, fastest. The default choice for straightforward single-object reads.
2. Extract — reads one or more related objects, supports formulas, nested output and custom JSON paths. Use it when Turbo Extract cannot express the requirement, and accept the extra processing cost.
3. Transform — pure JSON-to-JSON reshaping with no database access at all. Used to adapt an external payload to an internal structure, or vice versa.
4. Load — writes to Salesforce, supports insert, update and upsert, and can create related records in one definition by linking a child's lookup to a parent created earlier in the same definition.
5. The decision rule in practice: start with Turbo Extract, step up to Extract only when a relationship or formula forces it, and never use an Extract where a Transform would do, because an Extract implies a query you may not need.