It refers to the data. The numbers. The pathing, interactions, and everything like that.
The game is split into 3 parts for players: Skill, knowledge, and calls/shotcalling. Knowledge is the information - "what's Garen's Q's cooldown?", for example. Calls are the application of that knowledge on the long-term/macro scale - "Should we go for Baron now?". Skill is the small-scale execution of things - Dodging abilities, pulling off combos, CSing, etc.
All three have a bit of overlap. Knowledge leads a lot into calls, (You can know whether or not it's smart to go for Baron, for example, based on their ultimates, summs, and your team's power at the time versus theirs), and assists with skills (You know what abilities you have to play around, or when to go in for a trade, or when to use your CC). Calls lead to situations with skill, and skill lets you actually do what you intended to do.