The Ribbon is the name given to the tabbed toolbar at the top of the editor window, similar to the design used in Office 2007 and newer.
By default the ribbon is hidden until you click one of the ribbon tabs. You can toggle permanently showing the ribbon by clicking the Pin/toggle ribbon button in the top right.
Keyboard shortcuts can be identified either by hovering a button on the ribbon, or pressing Alt which will show keyboard shortcuts on-screen.
The Home tab
The Home tab has the standard functions common to most software: Cut, Copy, Paste, Undo and Redo.
The Delete, Select All and Select None buttons affect the current selection in either the Event Sheet View or Layout View.
Configurations allow you to set up different versions of your project without having to save multiple projects to disk. Active configurations sets which configurations are currently being edited. Since only one configuration can be displayed in the editor at a time, this is chosen with the Display configuration, which must also be an active configuration.
The Online section contains some web links you may find useful.
The Preview section has buttons to preview or debug the project and export a game ready for publishing.
The Go section allows you to bring up the Start page if you closed it.
The View tab
The Bars section allows you to show or hide the various user interface bars in the Construct 2 editor by clicking the checkboxes. See the Interface section for more information about each bar.
The Zoom section can be used to zoom both the Layout View and Event Sheet View.
The Grid options and Grid size sections only apply to the Layout View. By enabling Snap to Grid, moving and placing objects will snap them to an invisible grid with the given cell sizes. The grid can optionally also be shown in the Layout View.
The Theme allows you to choose different visual styles for the Construct 2 user interface. This is purely cosmetic and does not affect any functionality of the editor.
The Display section also only affects the Layout View. Show collision polys will render outlines of each object's collision polygon in the Layout View itself if enabled. The color of the collision polygon lines can be changed in Preferences. The Translucent inactive layers mode will show all layers apart from the active one (selected in the Layers Bar) at 33% opacity. The translucent layers are also locked so objects on them cannot be selected. This can be a convenient mode for editing individual layers.
The Events tab
The Events tab only applies to the Event Sheet View. If a Layout view is open all its buttons will be disabled.
The Add buttons in the Events section provide quick ways to add a new event, condition, action, sub-event, event group, global or local variable, event include or comment. If you have something in the event sheet selected, the new item will be added next to the selection.
Disable allows you to toggle conditions, actions or entire events on and off. A disabled event appears crossed out, and is effectively deleted - it will not run or affect the game in any way. However, you can bring it back at any time by clicking Disable again. This can be useful for testing.
The Bookmarks section allows you to toggle bookmarks on the selected event, and navigate to the next and previous bookmarks in the project. These can also be viewed with the Bookmarks Bar.
The Breakpoints section allows you to toggle breakpoints on events, conditions and actions, or remove all breakpoints from the project.
The Search section allows you to filter all the events in the current event sheet by a phrase. If an event contains the search text anywhere inside it, the event remains in the view, otherwise it is removed. This can be very useful to locate events related to a particular object, or to find something in a long event sheet. The Clear Search button (or pressing Escape) shows all events again.
The Show 'Add action' links can be used to hide or show the Add action link in every event. These provide a quick way to add new actions. However, they can significantly increase the vertical height of the event sheet making it a little harder to read or find events. If you want to review an event sheet you might find it useful to turn these links off. Actions can still be added to events even when the links are hidden by the Add action button in the ribbon or right-click menu.