The former (the first of two items mentioned).
A案とB案があるが、前者の方がコストが低い。
There are plans A and B; the former has lower costs.
質問は二つあります。前者は仕様に関するもの、後者は納期についてです。
I have two questions. The former is about the specifications; the latter is about the delivery date.
前者を優先し、後者は次回に回しましょう。
Let's prioritize the former and leave the latter for next time.