The package without the addition +secretstorage is the base package yt-dlp .
The other one is a variant you can install exclusively. While both of them use +default as dependency.
Name : yt-dlp
Summary : A command-line program to download videos from online video platforms
Description : yt-dlp is a command-line program to download videos from many different online
: video platforms, such as youtube.com. The project is a fork of youtube-dl with
: additional features and fixes.
Name : yt-dlp+secretstorage
Summary : Metapackage for yt-dlp: secretstorage extras
Description : This is a metapackage bringing in secretstorage extras requires for yt-dlp.
: It makes sure the dependencies are installed.
Name : yt-dlp+default
Summary : Metapackage for yt-dlp: default extras
Description : This is a metapackage bringing in default extras requires for yt-dlp.
: It makes sure the dependencies are installed.