The Weldopedia data dictionary

Quick, easy-to-grasp definitions of all the key data terms you need to know.
Common Table Expression (CTE)

A Common Table Expression (CTE) is a tool for keeping SQL queries simple. It creates a result set that exists only temporarily in a larger query.

Customer Acquisition Cost

Customer Acquisition Cost is a metric that determines the amount of money your company spends to acquire a customer.

Data lineage

Data lineage is the mapping of how data flows from the source through its extraction, transformation, and loading into its end destination.

Data modelling

Data modelling is a process that brings certain pieces of data together into a metric or table that enables data analysis and activation.

Data pipeline

A data pipeline is a combination of data processes that move data from a source system to a target destination, usually through ELT or reverse-ETL.

Data source

A data source is the original location a piece or set of data comes from, and the number of data sources companies have has been quickly increasing.

Data warehouse

A data warehouse is the central repository for a company’s data, bringing data from various sources into a single space for analysis and activation.


ELT stands for Extract, Load, and Transform. It's a process by which data is replicated from a source to a destination (often a data warehouse).


Reverse-ETL is a data activation process through which data is synced from your data warehouse into your work tools.