Code signing certificates that are issued by public and independent certificate authorities (CAs) generate digital signatures that are recognized and classified as trustworthy by all standard operating systems and application platforms worldwide.
CAs like DigiCert, GlobalSign or Sectigo are subject to strict standards for issuing certificates and must undergo regular audits in order to guarantee compatibility with operating systems like or applications like Microsoft, Apple, Google or Mozilla.
With signed code, operating systems and applications check the issuing CA and the hash of the certificate used for the signature. If the CA is not included in the trusted list (root store) or if the hash is not identical, the signature is not trusted and the verification fails.
With private code signing, no such "seal" is added by a third and independent party. For this reason, we recommend acuiring a trusted code signing certificate for publishing and distributing software online so that the software application is labeled as safe to use.