The term "water challenge" can refer to different things, depending on the context. Here are two possible meanings:

1. TikTok "Water" Challenge: This is a dance challenge that has gone viral on TikTok, inspired by a particular style of dance called Bacardi that originates in South Africa. The challenge involves shaking hips and kicking legs before pouring a bottle of water down the back to the lyrics "Make me sweat, make me hotter, make me lose my breath, make me water". The routine was created by South African singer and dancer Tylas choreographer, Litchi, and has over 150 million views on TikTok.

2. 30-Day Water Challenge: This is a challenge to drink more water every day for 30 days in a row. The goal is to drink one more glass of water than you normally would each day. The challenge is meant to help people stay hydrated, which is important for overall health. Some tips for the challenge include keeping a pitcher or big water bottle in plain view to remind yourself to drink up, switching up the water bottle for each day of the week, and finding a "water buddy" to finish the challenge with you.

In summary, the "water challenge" can refer to a dance challenge on TikTok or a challenge to drink more water every day for 30 days.