Remmina
Connects to other computers over RDP, VNC and SSH.
Installs from Ubuntu's own software archive.
Remote Desktop Connection comes with Windows, so it won't be on a new Linux PC. This free app does the same job, and TuxPick installs it for you.
Install Remmina with TuxPickIt works on Ubuntu 22.04 and 24.04, and on systems built on them like Zorin OS and Pop!_OS.