The term crimping means to press, make an impression, fold or even deform by folding.
In electrical installation the term crimping is used to describe the mechanical compression of a sleeve around a conductor to make a firm mechanical connection between the conductor and the connector.
Crimp connections have a large extent replaced soldered connections and have proven extremely suitable for the task over the years in which they have been in use. They are only permitted, however, if they satisfy the required DIN IEC values.
The prerequisite for this is that the conductor, contact, crimping tool and tool setting are all coordinated.