iTunes is a program that lets you do lots of things with music and other things you can listen to or watch on your computer or Apple device like the iPhone or iPad. It first came out in the year 2001 and was made by a company called Apple.
Back then, lots of people were still buying CDs (these are round discs that have music or other things recorded on them) or downloading music illegally (which means taking music without paying for it). Apple wanted to make a way for people to buy digital music easily and legally, so they made iTunes.
When iTunes first came out, it was only available on Apple computers and it only let you organize and listen to music. But soon, Apple added the iTunes Store, which let you buy and download digital music, movies, TV shows, and even books.
Nowadays, iTunes has changed a lot. It's still a program that lets you buy and organize music, movies, and TV shows, but it's also the way lots of people listen to podcasts (which are like radio shows that you can listen to anytime) and audiobooks (which are like books that someone reads to you).
iTunes is also important because it helps people get music and other things onto their Apple devices like the iPhone, iPad, and iPod. Before iTunes, it was more difficult to get your music from your computer onto your iPod. But with iTunes, you can easily sync (which means match up) your music and other things between your computer and your device.
Overall, iTunes has been really important because it's made buying and managing digital music and other things much easier and more convenient.