It is Creative Commons - Attribution-NonCommercial 4.0 International
You are free to:
Share — copy and redistribute the material in any medium or format
Adapt — remix, transform, and build upon the material
The licensor cannot revoke these freedoms as long as you
follow the license terms.
Under the following terms:
Attribution — You must give appropriate credit, provide a link to
the license, and indicate if changes were made. You may do so in
any reasonable manner, but not in any way that suggests the licensor
endorses you or your use.
NonCommercial — You may not use the material for commercial purposes.
No additional restrictions — You may not apply legal terms or
technological measures that legally restrict others from doing anything
the license permits.
The full details:
here