Soldering methods are divided based on different aspects (according to DIN 8505). People differentiate between soft soldering and hard soldering.
Soft soldering includes the soldering with solders, where the liquidus temperature is below 450°C. With hard soldering, however, the liquidus temperature of the solders is between 450°C and 900°C. Usually, hard soldered connections are mechanically stronger than soft soldered connections.
For higher temperatures, people refer to the process as high-temperature soldering or even welding. While with soldering, only the solder is melted to connect parts; with welding, the metals that are to be connected are melted as well.
Overview of possible soldering methods: