When it comes to managing startup programs on your Mac, there are several ways to go about stopping them from running without having to restart. One method involves using Terminal and typing `launchctl unload` followed by a space and the full path to the launch item you want to stop. This can be particularly useful when dealing with programs that run constantly in the background or at scheduled intervals.

In addition to using Terminal, you can also manage startup programs through the Launch Agents folder located within your user directory. Here, you'll find `.plist` documents that specify what should launch and under what circumstances. Instead of opening apps directly, launchd loads specially-formatted `.plist` files to determine which programs should run at startup.

Another way to stop a program from running at startup is to check the Login Items list within System Preferences. Everything in this list - whether added by you or an app - opens automatically when you log in. To remove an item, simply select it and click the minus button.

In older versions of macOS, there were two folders that held items designated to load when you started your Mac: `/Library/StartupItems` and `/System/Library/StartupItems`. However, Apple now discourages the use of these folders, and some old apps may still use them. If you find an unwanted item in one of these folders, you can simply drag it to the Trash to prevent it from loading automatically the next time you start your Mac.

Finally, if you're dealing with a launch daemon or agent that's controlled by the launchd process, you can manage it through Terminal as well. This provides more flexibility for developers but may be less transparent to users.

By following these steps, you should be able to effectively stop startup programs on your Mac and regain control over what runs automatically when you start your computer.