A backpack is a common and practical backpack style with two shoulder straps that can balance shoulder loads, making it suitable for various occasions such as daily life, work, study, and travel. Here are some features and advantages of backpacks:

1. Balanced weight sharing: The two shoulder straps of the backpack can evenly share weight, reducing the burden on one shoulder, making it more comfortable and suitable for long-term wear.

2. * Convenient to carry *: The backpack can distribute weight on both shoulders, making it easy to carry and less likely to cause poor posture or shoulder discomfort.

3. * Large capacity *: Backpacks usually have a large capacity and can accommodate various items, including books, electronic devices, clothing, etc., making them convenient for daily use and travel.

4. * Multi functional design *: Backpacks usually have multiple pockets and a sorting design, making it easy to organize and sort items, and easy to retrieve and store.