our company; our firm
Humble (kenjougo) term used when referring to one's own company to outsiders. Not used when speaking within the company.
I will explain about our company's products.
Our company is recruiting new employees.
Please contact our company for further details.
On behalf of our company, I would like to express our gratitude.
At our company, we carry out initiatives for environmental protection.
内 is a casual way to refer to one's own company, while 弊社 is the humble, formal term used in business writing and speech.
当社 is a neutral, formal way to refer to one's own company, while 弊社 is the humble form used specifically when speaking to outside parties.
自社 is neutral, whereas 弊社 humbly refers to one's own company when speaking to outside parties, especially in business correspondence.