Jajaja is how laughter is typed in Spanish speaking countries, the equivalent of hahaha in English, with the letter j pronounced like a strong h. The repeated string jajajajajja is common in text messages, comments and memes to show something is genuinely hilarious. As voice notes and soundboards grew popular, spoken versions of that typed laugh became shareable clips for chats and videos. It remains widely used because it crosses language barriers and works instantly as a laughing reaction.