This is the dude you chose at the start of the game, and he belongs to one of two factions, according to the in-game lore: BEAR or USEC. When you choose to play as a PMC in Escape From Tarkov, you are controlling your player created character. Luckily, you’ve stumbled upon this guide which should clear things up for you. But it’s not immediately apparent what the difference is.
To hop into a raid, you need to pick to play as a SCAV or PMC. If you’re new to Escape From Tarkov, you may be stumped by one of the early choices you’ll have to make upon booting up the game.