信封用英语怎么说

The English term for "信封" is "envelope".

Envelopes are a type of paper container used to hold letters, cards, and other documents. They typically have flaps that open to reveal the contents inside and a seal or stamp that indicates who the letter is intended for. Envelopes can be made from a variety of materials including paper, plastic, and foil.

In addition to traditional envelopes, there are also digital versions that can be sent electronically through email or messaging apps. These digital envelopes often have a similar appearance to traditional envelopes but are completed in a digital format.

Overall, envelopes are an important tool for communication and organization. Whether using traditional or digital versions, they play a crucial role in keeping personal and professional correspondence secure and organized.