Headquarters, HQ, Head Office, Company Headquarters
noun
The origin company is where everything in your company comes from. This is your main base. This is your headquarters.
ほんしゃ
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
本社はポートランドにあります。
The head office is in Portland.
本社にはスタッフが千人ほどいます。
The HQ has a staff of about 1,000.
本社のサーバーに不正アクセスがあったらしい。
It seems like there was unauthorized access to the headquarters' server.