| #https://www.notion.so/n8n/Frontmatter-432c2b8dff1f43d4b1c8d20075510fe4 | |
| contentType: explanation | |
| # Transforming data | |
| n8n uses a predefined [data structure](/data/data-structure.md) that allows all nodes to process incoming data correctly. | |
| Your incoming data may have a different data structure, in which case you will need to transform it to allow each item to be processed individually. | |
| For example, the image below shows the output of an [HTTP Request](/integrations/builtin/core-nodes/n8n-nodes-base.httprequest/index.md) node that returns data incompatible with n8n's data structure. The node returns the data and displays that only one item was returned. | |
|  | |
| To transform this kind of structure into the n8n data structure you can use the data transformation nodes: | |
| * [Aggregate](/integrations/builtin/core-nodes/n8n-nodes-base.aggregate.md): take separate items, or portions of them, and group them together into individual items. | |
| * [Limit](/integrations/builtin/core-nodes/n8n-nodes-base.limit.md): remove items beyond a defined maximum number. | |
| * [Remove Duplicates](/integrations/builtin/core-nodes/n8n-nodes-base.removeduplicates/index.md): identify and delete items that are identical across all fields or a subset of fields. | |
| * [Sort](/integrations/builtin/core-nodes/n8n-nodes-base.sort.md): organize lists of in a desired ordering, or generate a random selection. | |
| * [Split Out](/integrations/builtin/core-nodes/n8n-nodes-base.splitout.md): separate a single data item containing a list into multiple items. | |
| * [Summarize](/integrations/builtin/core-nodes/n8n-nodes-base.summarize.md): aggregate items together, in a manner similar to Excel pivot tables. | |