understanding --context and --dockerfile

[m-panov-sdg]

Hello.
I am trying to understand, do I need to pass in the --dockerfile argument directory from --context argument?

Example

• The first one: --dockerfile without $CI_PROJECT_DIR

    - /kaniko/executor
        --context "$CI_PROJECT_DIR"
        --dockerfile "$DOCKERFILE"

• The second one: --dockerfile with $CI_PROJECT_DIR

    - /kaniko/executor
        --context "$CI_PROJECT_DIR"
        --dockerfile "$CI_PROJECT_DIR/$DOCKERFILE"

both options will work, but which one is correct, and what difference?