The large difference
From time to time somebody says ‘ConEmu is still running the Windows cmd.exe, it’s not a bash’.
That is absolutely wrong.
Terminals
ConEmu is a ‘local terminal’ or ‘console window’, these are synonyms. There are many different terminals for all OS and tastes.
Few examples: iTerm2, konsole, guake, xterm, mintty.
Command-line interpreters
When user starts terminal, it runs some console application.
Few examples: Powershell, cmd.exe, bash, zsh, iPython.
These applications and many others all are command-line interpreters (CLI) or ‘shells’. They do ‘read-evaluate-print’ cycle, aka command execution.
Bottom line
ConEmu is a Windows terminal where you can run any shell you want.