Timeline is a powerfull unity tool that permit to create a temporal sequence of instructions.

Create Timeline Asset

In Project right click and select Create>Timeline

That operation create a *.playable file that represent a timeline asset.

Timeline Tracks

Here is the official doc about tracks

On the left side of a Timeline we can see which tracks are used. A Track is a type of clips and is shown in horizontal. To add one Track just click the + button and choose the Track.

Timeline Clips

The Clips holds the data and the behaviour to execute at specific time of the timeline. Every different Track has different Clips.

One track could have more than one clip with the max of one per frame (or an interpolation beetwen 2)

Problems

At low fps the timeline execution could lose some frame, so if we have very small ( less than 5 frame) clips, these could be jumped out.

Forum talks

Conclusion

Timeline is a great tool for hardcode easily secuences of action.