> For the complete documentation index, see [llms.txt](https://docs.coupler.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.coupler.io/functionality/data-set/combining-data.md).

# Combining Data

Coupler.io allows you to fetch data from several sources at the same time

<table data-view="cards"><thead><tr><th></th><th></th><th data-hidden data-card-cover data-type="image">Cover image</th><th data-hidden data-card-target data-type="content-ref"></th></tr></thead><tbody><tr><td><strong>Join data</strong></td><td><em>all the elements from the left set are kept while only matching elements from the right set are included</em></td><td><a href="/files/NE7dYcjFZNEd0YlnM9ko">/files/NE7dYcjFZNEd0YlnM9ko</a></td><td><a href="/pages/HC2Kdc1x6P1Cb4ev6NMx">/pages/HC2Kdc1x6P1Cb4ev6NMx</a></td></tr><tr><td><strong>Append data</strong></td><td><em>merging values for the same data attribute from two or more data sets and placing them under the same column(s) in the destination file.</em> </td><td><a href="/files/a9291wbhEmqqcdNv6g0w">/files/a9291wbhEmqqcdNv6g0w</a></td><td><a href="/pages/DRZ4XrnyiexEgvqceZLi">/pages/DRZ4XrnyiexEgvqceZLi</a></td></tr><tr><td><strong>Aggregate data</strong></td><td><em>summarizing and revealing key insights of your data by performing operations like sum, average, count, min, or max on specific columns and consolidating the results in the destination file</em></td><td><a href="/files/gLgbM8kPzafWWzwjcToJ">/files/gLgbM8kPzafWWzwjcToJ</a></td><td><a href="/pages/FpymVmiSpgrOtHT3Xr2l">/pages/FpymVmiSpgrOtHT3Xr2l</a></td></tr></tbody></table>


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