As you make your way across the desert you will find the occasional white orb thing, often in hidden locations. These are glyphs. Collecting one of these will increase the length of your scarf and in turn, will increase the amount of time you can spend flying once it is fully charged.
If you collect all of these you will unlock the “History” trophy. Even you you have no interest in the trophy, it is still useful to pick these up as flying is the best part of the game. Who doesnt want to spend more time flying!
Anyway, the video guide below is your best start if you are looking to find all of the Glyphs in Journey.