Celery serializes task messages and results to transmit them over the network. Supported serializers include:

• JSON: Default, cross-platform compatible, human-readable
• Pickle: Python-specific, supports complex objects but has security risks
• YAML: Human-readable, less common
• msgpack: Binary format, more efficient than JSON

Configuration example:

app.conf.task_serializer = 'json'
app.conf.result_serializer = 'json'
app.conf.accept_content = ['json']