githubへのpush時のエラーについて

git push origin masterコマンドを実行すると以下のエラーが発生しました。

! [rejected] master -> master (fetch first)
error: failed to push some refs to 'https://github.com/〇〇/〇〇.git'
hint: Updates were rejected because the remote contains work that you do
hint: not have locally. This is usually caused by another repository pushing
hint: to the same ref. You may want to first integrate the remote changes
hint: (e.g., 'git pull ...') before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.

次にgit fetchを試すとhintが以下に変更されました。

error: failed to push some refs to 'https://github.com/〇〇/〇〇.git'
hint: Updates were rejected because the tip of your current branch is behind
hint: its remote counterpart. Integrate the remote changes (e.g.
hint: 'git pull ...') before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.

hintの内容もエラー内容もわからないので解決策がわかる方　どなたかお力をお貸しいただけますでしょうか。
宜しくお願い致します。