LoRa
LoRa is an abbreviation of 'Long Range Low Power' and enables sending small amounts of information between objects with very low power. LoRa receivers are very sensitive due to spread spectrum, allowing the sender to send with very low power even when noise is high and distance are far. See for instance www.link-labs.com/what-is-lora/ for a more in depth discussion of LoRa spread spectrum Modulation.
LoRaWAN
LoRa Wide-Area-Network (LoRaWAN) uses LoRa modulation to build a network of a few gateways (cell-towers) to communicate with many devices. Basically it is a set of rules on how to communicate and what protocols to use. The full specifications of the LoRaWAN protocol can be requested at the LoRa Alliance for free. Please refer to the LoRa Alliance website for the latest version.
LoRaWAN is designed to enable many devices to send uplink messages (from a device to the network). LoRaWAN also enables replying with a downlink message (from server to device), although the number of downlink messages is limited (for reasons explained here).
Note: KPN LoRa is a LoRaWAN Network and when we talk about LoRa we imply LoRaWAN.