Your music can be delivered to digital stores and streaming platforms by:
• a distributor
• a record label working with a distributor
Here are the 10 most popular distributors
Each service is unique, so you should try to learn more info before picking one. Most charge a fee or commission. All of them handle all the licensing and distribution, and pay your streaming royalties. It is believed that streaming will continue to increase over the next 10 years, leaving only a 5% or less to physical music sales.
Here is a very nice youtube video that compares 4 distribution Services: Cd Baby, Tunecore, Distrokid, OneRPM:
Remember that, in order to upload your tracks, you need album artwork, which must follow these specifications: Size: 3000 x 3000 pixels, File Format: .jpg, Color Format: RGB.