Editing path segments works similarly in Adobe applications. You can edit a path segment at any time, but editing existing segments is slightly different from drawing them. Keep the following tips in mind when editing segments:
If an anchor point connects two segments, moving that anchor point always changes both segments.
When drawing with the Pen tool, press Ctrl (Windows) or Command (Mac OS) to temporarily activate the last used selection tool (Illustrator) or the Direct Selection tool (InDesign and Photoshop) so that you can adjust segments you’ve already drawn.
When you initially draw a smooth point with the Pen tool, dragging the direction point changes the length of the direction line on both sides of the point. However, when you edit an existing smooth point with the Direct Selection tool, you change the length of the direction line only on the side you’re dragging.
To create a corner point, position the Pen tool where you want to end the new segment, and click. If you are extending a path that ends at a smooth point, the new segment will be curved by the existing direction line.
To connect the path to another open path,
click an endpoint on the other path. When you precisely position
the Pen tool over the other path’s endpoint, a small merge symbol appears
next to the pointer.
To connect a new path to an existing path, draw the new path near the existing path, and then move the Pen tool to the existing path’s (unselected) endpoint. Click that endpoint when you see the small merge symbol that appears next to the pointer.
Hold down the Shift key in addition to the arrow key to move 10 pixels at a time.