An end-entity or leaf certificate is any certificate that cannot sign other certificates.
For instance, TLS/SSL server and client certificates, email certificates, code signing certificates, and qualified certificates are all end-entity certificates.
en.wikipedia.org/wiki/Public_key_certificate#Self-signed_and_root_certificates
An end-entity certificate identifies the user, like a person, organization or business.
An end-entity certificate cannot issue other certificates.
An end-entity certificate is sometimes called a leaf certificate since no other certificates can be issued below it.