Basic Encoding Rules (BER) is a standard for encoding ASN.1 data. It is by far the most common standard for doing so, being used in LDAP, TLS, SNMP, RDP, and other protocols. Like Distinguished Encoding Rules (DER), Canonical Encoding Rules (CER), and Packed Encoding Rules (PER), Basic Encoding Rules is a specification created by the https://www.itu.int/en/pages/default.aspx, International Telecommunications Union, and specified in http://www.itu.int/rec/T-REC-X.690/en, X.690 - ASN.1 encoding rules
Canonical Encoding Rules (CER) is a standard for encoding ASN.1 data. CER is often used for cryptgraphically-signed data, such as X.509 certificates, because CER's defining feature is that there is only one way to encode each data type, which means that two encodings of the same data could not have different cryptographic signatures. For this reason, CER is generally regarded as the most secure encoding standard for ASN.1. Like Basic Encoding Rules (BER), Canonical Encoding Rules (CER), and Packed Encoding Rules (PER), Canonical Encoding Rules (CER) is a specification created by the https://www.itu.int/en/pages/default.aspx, International Telecommunications Union, and specified in http://www.itu.int/rec/T-REC-X.690/en, X.690 - ASN.1 encoding rules
Distinguished Encoding Rules (DER) is a standard for encoding ASN.1 data. DER is often used for cryptgraphically-signed data, such as X.509 certificates, because DER's defining feature is that there is only one way to encode each data type, which means that two encodings of the same data could not have different cryptographic signatures. For this reason, DER is generally regarded as the most secure encoding standard for ASN.1. Like Basic Encoding Rules (BER), Canonical Encoding Rules (CER), and Packed Encoding Rules (PER), Distinguished Encoding Rules (DER) is a specification created by the https://www.itu.int/en/pages/default.aspx, International Telecommunications Union, and specified in http://www.itu.int/rec/T-REC-X.690/en, X.690 - ASN.1 encoding rules