istio.io/content/en/docs/reference/glossary/injection.md

title	test
Injection	n/a

Injection, or sidecar injection, refers to the use of mutating webhooks to modify pod specifications at creation time.

Injection can be used to add the Envoy sidecar configuration for mesh services or to configure the Envoy proxy of gateways.

See Installing the sidecar for more information.