Answer: Let's use a building construction as an example of a project.
Step-by-step explanation:
Lag is the delay of a successor activity and represents the time between this activity and a previous activity.
Finish to start: means a predecessor activity A must finish before the successor activity B starts. An example is constructing the roof a building before painting the interior.
Finish to finish: means the predecessor activity must finish for the successor activity to finish. An example is laying plumbing pipes and inspecting the plumbing pipes.
Start to start: means the predecessor activity must start for the successor activity to start. An example is writing a brochure to sell out buildings and the subsequent editing.
Start to finish: means the predecessor activity must start for the successor activity to finish. An example is a construction supervisor A cannot leave his post until construction supervisor B resumes.