Explain if the "deploy" commands builds the subgraph all the time

[PaulRBerg]

I was looking to understand if the deploy command in the CLI runs the build command each time, but I wasn't able to figure this out from the --help output:

bun run graph deploy --help
 ›   Warning: @graphprotocol/graph-cli update available from 0.96.0 to 0.97.0.
Deploys a subgraph to a Graph node.

USAGE
  $ graph deploy [SUBGRAPH-NAME] [SUBGRAPH-MANIFEST] [-h] [-g <value>] [--deploy-key <value> | --access-token <value>] [-l <value>] [-i
    <value>] [--ipfs-hash <value>] [--headers <value>] [--debug-fork <value>] [-o <value>] [--skip-migrations] [-w] [--network <value>]
    [--network-file <value>]

FLAGS
  -g, --node=<value>           Graph node for which to initialize.
  -h, --help                   Show CLI help.
  -i, --ipfs=<value>           [default: https://api.thegraph.com/ipfs/api/v0] Upload build results to an IPFS node.
  -l, --version-label=<value>  Version label used for the deployment.
  -o, --output-dir=<value>     [default: build/] Output directory for build results.
  -w, --watch                  Regenerate types when subgraph files change.
  --access-token=<value>
      --debug-fork=<value>     ID of a remote subgraph whose store will be GraphQL queried.
      --deploy-key=<value>     User deploy key.
      --headers=<value>        [default: [object Object]] Add custom headers that will be used by the IPFS HTTP client.
      --ipfs-hash=<value>      IPFS hash of the subgraph manifest to deploy.
      --network=<value>        Network configuration to use from the networks config file.
      --network-file=<value>   [default: networks.json] Networks config file path.
      --skip-migrations        Skip subgraph migrations.

DESCRIPTION
  Deploys a subgraph to a Graph node.

I'm not sure if deploy will always generate a new build or will it use the existing build directory?