---
title: "How is synchronous mode different from asynchronous?"
source_url: https://dev.digicert.com/trustcore-sdk/nanossl/faqs/how-is-synchronous-mode-different-from-asynchronous.html
---

**Question:** What is the difference between synchronous and asynchronous communication?

**Answer:** Synchronous communication occurs in a set order of operations. Data is sent and received within each routine while the calling code waits or blocks. Asynchronous communication is non-blocking, allowing applications to process data in an event-driven model and using callbacks to flag when data has arrived.