When animating, i just realised that sometimes when i add a keyframe, it appears in the dopesheet but not in the timeline!! Why?
The timeline and dopesheet are very different things. The timeline isn't very interactive. The only thing you can do with it is change what frame your on and add markers. The dopesheet allows to move keyframes, copy keyframes, and way more. The timeline will only show keyframes for the object that's currently selected. but you can't do anything with a keyframe on the timeline.
Both are different and have different usage. From it's name, the Timeline allows you to change the time of the animation played. Along with the current frame, only inserted keyframes (using
I) will be displayed on the timeline. More details can be found in blender's manual Timeline Editor
While Blender's Dopesheet gives you a "bird's eye-view" of everything occurring within the seen. More details can be found in Dopesheet
For future reference for anyone who has a similar issue, I would like to recommend that you use the middle mouse button to look around in your timeline. I had the same issue as the one above but upon closer inspection i realized that i had not looked futher up my timeline and that was the issue.
Hope this helps!