Communication comes in many forms, and throughout history humans have been creative with how they communicate with each other and record information; these knotted strings the Inca used to keep records, called quipu (or khipu), are a perfect example of this.
From the video description:
“One of the great mysteries of ancient Peru is that the Inca did not have a system of writing, but communicated with a system of strings tied with knots. For the first time, centuries-old knotted textile accounting records known as quipus were found buried with well-preserved organic material. They were found at the archaeological site of Incahuasi, the base of operations for the Inca expansion along Peru’s southern coast.”
Learn more about quipu and see how the British Museum’s Conservator Nicole Rode is migrating ancient Inca data to an opensource database: