this institution; the main institution
Refers to the institution where the speaker/writer belongs (e.g., this hospital, this university) or the main/head institution of a group. Common in formal announcements and news.
本院では、最新の医療機器を導入しております。
This hospital has introduced the latest medical equipment.
本
The main hospital and the branch clinic have different consultation hours.
本院 is the main temple or headquarters of a temple organization, in contrast to 別院, its branch temple.
Compound of 本 (main, this) and 院 (institution). The reading ほんいん follows standard on'yomi.