Let's make this really easy for you if you aren't sure exactly what this even means. It is a strategy (or road map) that creates a customer step by step journey to get them to the BUYING from you stage, or whatever else you are directing them to do on this funnel.
Step 1: Getting a potential client to understand you exist... they might not even know who you are or what you do this is your first step... explain it all to them. They need to know why they need to learn more about you. This is also the step where you plant that little seed of need for you and your services etc.
Step 2: they are considering purchasing from you now what? Now you strengthen that trust, share your social proof, provide value.
Step 3: Retarget them in other places, they are already interested but it takes seeing you and what you offer more than once. Volume of content is key here and cohesiveness in the message.
Step 4: Keep at it... if at first you don't succeed, tweak and try again! Don't give up easily!