This video shows the market cap growth of FAANG companies from 2008 to 2019. FAANG companies are Facebook, Apple, Amazon, Netflix, and Google (Alphabet).
Market cap is the number of shares times the price of a single stock. It's a simple measurement to evaluate the size of a company and allows to compare the size of different companies.
Facebook stock only appears in the chart in 2012 when it IPO'ed.