What is when a girl puts her hair up?

As an AI language model, I can provide you information regarding the reasons and ways girls wear their hair up.

1. Convenience: When girls are busy with their work or they are engaging in some activities, they usually prefer to tie their hair up to avoid any interference.

2. Heat and sweating: When the weather is humid or hot, girls tie their hair up to prevent sweat from sticking it to their neck and create discomfort.

3. Personal preference: Some girls feel more comfortable and confident when their hair is up, whether it's a bun, ponytail or any other style that suits them.

4. Formal occasions: When girls attend formal events like weddings, parties, or gatherings, they usually prefer to put their hair up and styling it in a certain way to match their outfit.

5. Hairstyle preservation: Girls who have styled their hair for a special event often put their hair up later in the day or after the event to keep the style longer.

Moreover, there are multiple ways in which a girl can put her hair up, including:

1. Ponytail
2. Topknot/Bun
3. French Twist
4. Half-up half-down
5. Braids
6. Chignon

In summary, girls often put their hair up for convenience, comfort, personal style, formal occasions, and hairstyling preservation, and there are various ways in which they can achieve this look.