Means "in addition to" or "besides" — used to add another item or point to what has already been mentioned.
彼は英語に加えフランス語も話せる。
In addition to English, he can also speak French.
会費に加え、材料費が別途必要です。
In addition to the membership fee, materials costs are required separately.
最近の研究に加え、新しいデータも考慮に入れるべきだ。
In addition to recent studies, new data should also be taken into account.