To copy and paste on a Chromebook, the most common way is to use keyboard shortcuts: press Ctrl + C to copy the selected text or item, then move the cursor to the target location and press Ctrl + V to paste it. Additional methods include:

• Using the touchpad: highlight the text, tap the touchpad with two fingers to open the context menu, and select "Copy." Then move to the location, tap with two fingers, and select "Paste."
• Using a mouse: highlight the text, right-click to open the context menu and choose "Copy." Move the mouse to the destination, right-click, and pick "Paste" or "Paste without formatting."
• On touchscreen Chromebooks: double-tap the text, adjust the selection handles, choose "Copy" from the pop-up menu, then tap and hold where you want to paste and select "Paste."

These methods work for text, images, documents, and other items that can be copied and pasted on Chrome OS.