Short answer: the Mac has no taskbar. The strip of icons at the bottom is the Dock, and unlike Windows there is no "lock the taskbar" checkbox anywhere in System Settings. macOS has the settings but never gave them a switch.
Four Terminal commands do it, and they are below.
Search a Mac’s settings for "taskbar" and nothing comes back, so the feature is hard to look up. The feature exists under different names:
The menu bar along the top is a separate thing again, and it is not part of the Dock. Nothing below affects it.
Windows put "Lock the taskbar" in a right-click menu for years. macOS has never had that control, and looking for it is the reason most people give up.
macOS has four settings that exist and work but have no interface. Setting one makes the matching control in System Settings stop responding, so you can see that it took:
defaults write com.apple.dock size-immutable -bool true
defaults write com.apple.dock position-immutable -bool true
defaults write com.apple.dock contents-immutable -bool true
defaults write com.apple.dock autohide-immutable -bool true
killall DockEach is independent, so lock only what you want. To release one, remove the key:
defaults delete com.apple.dock position-immutable; killall Dockkillall Dock restarts the Dock so the change takes effect. It does not close your apps and loses nothing; details are in what killall Dock does. The full list of keys is in every Mac Dock defaults command.
If Terminal is not somewhere you want to be, the same four settings are switches in Still Dock, and the three ways compared covers what each approach costs.
Locking the Dock is usually the first surprise. These are the next five, roughly in the order people meet them.
Windows can put a taskbar on every monitor. macOS has exactly one Dock and it follows your pointer: push the cursor to the bottom edge of any screen and hold it there, and the Dock moves to that display.
There is no setting for this, and position-immutable does not help, because the key governs only which edge of a screen the Dock sits on, and has no say over which screen it is on. The workarounds and what each costs are in how to keep the Mac Dock on one screen.
The Windows taskbar is a list of what is running. The Dock is mostly a launcher: it shows the apps you put there whether or not they are open, with a small dot under the ones that are running. Minimised windows collect at the right-hand end, past the divider.
The thing that actually lists open windows is Mission Control, on F3 or a three-finger swipe up.
The Dock can sit at the bottom, the left or the right. It cannot go along the top, because the menu bar lives there and macOS will not share that edge.
Dragging an icon out of the Dock removes the shortcut and nothing else. The app stays installed, and stays running if it was running. It vanishes in a puff of smoke, which is alarming the first time and reversible: find the app in Applications and drag it back, or open it and choose Keep in Dock.
On a Mac other people use, this is the one worth locking first. contents-immutable is what stops it.
macOS adds a section of recently used applications to the right of the Dock, so a Dock you arranged deliberately grows a tail of everything you have opened since. The recent apps section is a separate setting from the four above:
defaults write com.apple.dock show-recents -bool false
killall DockMore on it in how to stop recent apps appearing in the Dock.
Everything above is stored per account, so it applies to the login you run it in. On a machine several people share, or one the public touches, the reasoning changes and there is a page for each case: a shared Mac, a family Mac, a classroom Mac.
Not quite. It is the closest thing, but it is primarily a launcher and does not list open windows, and the notification area’s job belongs to the menu bar at the top.
You can move it to the bottom, turn off magnification and turn off recent apps, which makes it feel closer to a taskbar. You cannot make the Dock list every open window. Mission Control does that.
Nowhere. macOS has never shipped that control. The settings exist, which is why the commands above work, but Apple never gave them an interface.
Yes. They are stored in your account’s preferences, so a restart, a sleep and a macOS update all leave them alone.
No. These are your own preferences and they apply only to your login.
This is expected after running these commands: the controls stop responding once the matching key is set. If you did not set them and they are grey anyway, the grayed-out settings guide covers the other cause.