A P7B file is a security certificate file format based on the Public Key Cryptography Standards #7 (PKCS #7). It is primarily used to store digital certificates and certificate chains, which are essential for establishing secure communications over the internet. Unlike other certificate formats like CER or CRT, a P7B file is stored in a Base64-encoded ASCII format and specifically contains the certificate and its intermediate certificates but does not include the private key. This makes it ideal for exporting and importing public keys and certificate chains between servers, web browsers, and email clients. It is commonly used in Windows environments and by web servers like IIS (Internet Information Services) and Apache to facilitate SSL/TLS handshakes. The format is standardized by the IETF and is widely recognized for its ability to bundle multiple certificates into a single file, simplifying the process of installing a complete trust chain on a system. Because it uses ASCII encoding, the file content is human-readable as a block of text starting with '-----BEGIN PKCS7-----' and ending with '-----END PKCS7-----'.