Difference between these ENV variables

Trying to understand the difference between these two environment variables:

VAULT_ADDR
VAULT_DEV_LISTEN_ADDRESS

When running in dev mode, does only the later need to be set?

VAULT_ADDR is used by clients to point them at a Vault server. VAULT_DEV_LISTEN_ADDRESS is used by a Vault server running in dev mode to specify what interface and port to listen on.