What is the purpose of a technical 'appendix'?

The purpose of a technical appendix is to include supplementary information or data that supports the main text. This additional content can provide detailed explanations, raw data, calculations, or any other relevant material that enhances the reader's understanding of the main document without disrupting its flow. The appendix serves as a helpful resource for readers who may want to delve deeper into the specifics or verify the data presented in the main section. Rather than being central to the narrative, the appendix acts as a complement, ensuring that the main text remains focused while still offering valuable context and support for those who need it.