What are gloves with four fingers together?

This kind of gloves is called mittens.

Gloves with four fingers together are called "finger gloves". The design feature of this glove is to separate the thumb from the other four fingers so that the fingers can move more freely. The main reason of mittens is to improve the flexibility and maneuverability of hands, which is especially suitable for work or activities that require fine operation, such as photography, electronic equipment operation, sports and so on.