DSPTool.exe is unnecessary for almost every Dolphin user. I'm actually not even sure what it does myself, other than that it's occasionally useful for developers working on DSP stuff.
DolphinTool.exe lets you verify and convert disc images from the terminal. You can already do this from the GUI using Dolphin.exe, so you don't need this executable unless you specifically want to do those things from the terminal.
Updater.exe is Dolphin's automatic updater. If you want Dolphin to be able to update automatically, you may need to whitelist this in your antivirus program. Unlike the former two executables, this executable is launched automatically by Dolphin rather than being launched by the user.
DolphinTool.exe lets you verify and convert disc images from the terminal. You can already do this from the GUI using Dolphin.exe, so you don't need this executable unless you specifically want to do those things from the terminal.
Updater.exe is Dolphin's automatic updater. If you want Dolphin to be able to update automatically, you may need to whitelist this in your antivirus program. Unlike the former two executables, this executable is launched automatically by Dolphin rather than being launched by the user.