> For the complete documentation index, see [llms.txt](https://docs.ifreeq.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.ifreeq.com/developer/configure-in-platform/function-definition/overview.md).

# Overview

Defining product features is the first step in product development. Product functions are completed by a combination of 3 parts, including standard functions, custom functions, and cloud functions.

Standard functions: common functions of a product category 

![](https://2999784448-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MBlD-pGvqUEQDs9SdgH%2F-MBnbojjf_x1BTxJUdnC%2F-MBnf-crBNwTfTxwRtkc%2Fimage.png?alt=media\&token=c0c820cd-79bc-422f-a894-00a87c42c70a)

Self-defined functions: If standard functions do not meet your requirements, define custom functions. DPs are abstract representations of product functions, each of which can be defined by different functional types.  

![](https://2999784448-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MBlD-pGvqUEQDs9SdgH%2F-MBnbojjf_x1BTxJUdnC%2F-MBnfANoIEfgNXsxnX7L%2Fimage.png?alt=media\&token=e9396851-5c11-41c9-926e-034d480e9963)

Cloud functions: Timer and web page redirection are available. The Tuya Cloud's timer function allows you to set the on/off time and intervals and does not require hardware development. The web page redirection function allows you to go to a web page from the app, for example, go to an online mall or the product user manual page. 

![](https://2999784448-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MBlD-pGvqUEQDs9SdgH%2F-MBnbojjf_x1BTxJUdnC%2F-MBnfGJr8QzBEliGZDGZ%2Fimage.png?alt=media\&token=e8b66fca-b828-4da2-a9b4-0db251da293a)

 1、[Standard Functions](https://docs.tuya.com/en/iot/configure-in-platform/function-definition/standard-functions)

2、[Custom Functions](https://docs.tuya.com/en/iot/configure-in-platform/function-definition/custom-functions)

3、[Cloud Functions](https://docs.tuya.com/en/iot/configure-in-platform/function-definition/cloud-functions)