Saving changes by writing over an existing file (overwriting the previous version); be careful because the original is replaced.
作業中に誤って上書き保存してしまい、元のデータが戻せなかった。
I accidentally overwrote and saved during work, and couldn't restore the original data.
重要なファイルは別名で保存して、上書き保存を避けたほうが安全だ。
For important files it's safer to use 'Save As' and avoid overwriting.
最近のエディタは自動上書き保存機能があり、こまめに保存しなくても更新されることが多い。
Recent editors often have automatic overwrite-save features, so updates are often saved even without frequent manual saving.