How to understand data from the image_raw/compressed topic?

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I wanted to know what they represent and how to read data from the image_raw / compressed topic. For example, the laser / scan topic, your "ranges" data represent the distance to an object, so the image_raw / compressed topic represents exactly what? How can I use them?

Here is an example of the topic:

header:
    seq: 2068
    stamp: 
    secs: 689
    nsecs: 786000000
  frame_id: camera_link
   format: rgb8; jpeg compressed bgr8

data: [255, 216, 255, 224, 0, 16, 74, 70, 73, 70, 0, 1, 1, 0, 0, 1, 0, 1, 0, 0, 255, 219, 0, 67, 0, 6, 4, 5, 6, 5, 4, 6, 6, 5, 6, 7, 7, 6, 8, 10, 16, 10, 10, 9, 9, 10, 20, 14, 15, 12, 16, 23, 20, 24, 24, 23, 20, 22, 22, 26, 29, 37, 31, 26, 27, 35, 28, 22, 22, 32, 44, 32, 35, 38, 39, 41, 42, 41, 25, 31, 45, 48, 45, 40, 48, 37, 40, 41, 40, 255, 219, 0, 67, 1, 7, 7, 7, 10, 8, 10, 19, 10, 10, 19, 40, 26, 22, 26, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 255, 192, 0, 17, 8, 3, 32, 3, 32, 3, 1, 34, 0, 2, 17, 1, 3, 17, 1, 255, 196, 0, 31, 0, 0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 255, 196, 0, 181, 16, 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 125, 1, 2, 3, 0, 4, 17, 5, 18, 33, 49, 65, 6, 19, 81, 97, 7, 34, 113, 20, 50, 129, 145, 161, 8, 35, 66, 177, 193, 21, 82, 209, 240, 36, 51, 98, 114, 130, 9, 10, 22, 23, 24, 25, 26, 37, 38, 39, 40, 41, 42, 52, 53, 54, 55, 56, 57, 58, 67, 68, 69, 70, 71, 72, 73, 74, 83, 84, 85, 86, 87, 88, 89, 90, 99, 100, 101, 102, 103, 104, 105, 106, 115, 116, 117, 118, 119, 120, 121, 122, 131, 132, 133, 134, 135, 136, 137, 138, 146, 147, 148, 149, 150, 151, 152, 153, 154, 162, 163, 164, 165, 166, 167, 168, 169, 170, 178, 179, 180, 181, 182, 183, 184, 185...