# How is the Aggregate Transformation different from the Expression Transformation?

In the [*Aggregate* Transformation](https://documentation.astera.com/astera-data-stack-v10/dataflows/transformations/aggregate-transformation), you can apply different aggregate functions such as Sum, Count, First, Last, Min, Max, Average, Var, or StDev and derive values from the input.

<figure><img src="https://3083465318-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FsR50Wa7EwZGlmPSAMkkf%2Fuploads%2F0n4ioLnOG5Lzd8uoRLjx%2Fimage.png?alt=media&#x26;token=ac8956c6-2c1f-4ec7-b934-790e44746265" alt=""><figcaption></figcaption></figure>

Whereas in [*Expression* transformation](https://documentation.astera.com/astera-data-stack-v10/dataflows/transformations/expression-transformation), you can apply various functions such as string, date/time, financial, matching, logical, mathematical, regular expressions etc. on your incoming data or even write your own expressions in the expression layout builder.

<figure><img src="https://3083465318-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FsR50Wa7EwZGlmPSAMkkf%2Fuploads%2FOHLJuGjtdO5ENaYK2SqL%2Fimage.png?alt=media&#x26;token=461d665b-616d-414b-8b24-ea38a944ce1c" alt=""><figcaption></figcaption></figure>