Within The Company, In House, Inside The Company
noun, の adjective
When you're doing something inside the company you're doing it within the company or in-house. For example, we do our kanji in-house. It gives it that artisan flavor.
しゃない
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.
社内にデザイナーがいます。
The company has in-house designers.
社内では今、白のデスクが人気です。
White desks are popular in the company now.
会社のパーティについてのメッセージが社内メールで回ってきた。
A message about the company party came as an internal email.