+++
pre = "<b>3.5.1. </b>"
title = "Core Concept"
weight = 1
+++

## Scaling Job

It refers one complete process of scaling data from old sharding rules to new sharding rule.

## Data Node

Same as the [Data Node](/en/features/sharding/concept/sql/) in sharding/SQL.

## Inventory Data

It refers all existing data stored in data nodes before the scaling job started.

## Incremental Data

It refers the new data generated by application during scaling job.
