The Ruuvi range is short and consistent: the RuuviTag 4-in-1 measuring temperature, humidity, pressure and movement, the Tag Pro in 2-in-1, 3-in-1 and 4-in-1 versions, and the Ruuvi Gateway for remote monitoring of Bluetooth RuuviTag sensors.
The tags are Bluetooth, the Gateway is what gets the data out. Without it readings stay local to a phone in range; with it the same sensors can be followed from somewhere else, which is the difference between checking a reading and actually monitoring a site.
Pick the Pro variant by what you need to log: 2-in-1 for temperature and movement, 3-in-1 to add humidity, 4-in-1 to add pressure as well.
