Vacuum bottles are also known as insulated bottles, thermos flasks or vacuum flasks. They are a type of container that can keep liquids hot or cold for extended periods of time. The vacuum insulation technology used in these bottles helps to prevent heat transfer between the liquid inside and the environment outside. This means that hot drinks will stay hot and cold drinks will stay cold for hours. Some other common synonyms for vacuum bottles include: thermal bottles, insulated flasks, hot and cold bottles, travel mugs, and portable drink containers. Whatever name you use, these bottles are an essential item for anyone who loves to enjoy their hot or cold drinks on-the-go.