An SSL/TLS Certificate mainly contains the following information. It may include additional fields, but these are the most common.
Domain Name: Specific domain the certificate is issued for.
Subject: Identity of the certificate owner (organisation name and location).
Issuer: Information about the Certificate Authority (CA).
Public Key: Public key is used for encrypting data sent to the website.
Serial Number: Unique number assigned by the CA.
Validity Period: Timeframe during which the certificate is valid.
Signature Algorithm: Algorithm used by the CA to sign the certificate.
Signature: Digital signature of the issuing CA.
Subject Alternative Name (SAN): Optional field for multiple domain names or subdomains.