It allows you to play almost any PS2 game from your PC. Luckily for you, you don’t have to buy a PS2 again and go scavenging the internet for old PS2 discs.
You miss playing the classics like Tekken 5, God of War and San Andreas. You’ve probably sold your PS2 or chucked it out a long time ago. You want those nostalgic feels back! You haven’t played a PS2 game in years.