Parallelism; two things running side by side in the same direction or position. In geometry, lines that do not intersect and are in the same direction.
二本の線は互いに平行で交わらない。
The two lines are parallel and do not intersect.
平行定規を使って図面を引いた。
I drew the plan using a parallel ruler.
Things occurring concurrently; running at the same time or keeping pace with each other (e.g., projects running in parallel).
二つのプロジェクトが平行して進行しているため、調整が必要だ。
Because two projects are proceeding in parallel, coordination is necessary.
新製品の開発を平行して行うことで、時間短縮を図った。
By carrying out product developments in parallel, we shortened the time frame.
A figurative meaning: when discussions fail to agree and parties remain at cross-purposes (as in '走る平行線').
両者の主張はかみ合わず、話し合いは平行線をたどった。
The two parties' arguments didn't mesh, and the discussion ended up going nowhere.