Let’s Encrypt is a certificate that encrypts the connection between the web browser and the web server, like known and widely distributed SSL certificates. The difference to them is that it is free and uses a simplified issuance process. Let's Encrypt certificate comes closest to SSL certificates with domain validation.
An alternative to Let's Encrypt is the cPanel/Sectigo SSL certificates automatically installed with AutoSSL in cPanel.
The cPanel / Sectigo SSL certificates that are installed with AutoSSL are specially developed by cPanel with Sectigo. cPanel / Sectigo certificates have the same terms as Let's Encrypt. They are completely free, issued for a period of 3 months and are automatically renewed. The difference with Let's Encrypt is that the installation of the certificate is done automatically without user intervention.