Error: file_put_contents(/home/sdp/web/themes-production.sdp-platform.com/storage/framework/views/bd392427fda80954729f2981f50762bb.php): Failed to open stream: Permission denied

Difference between the terms, 'purchasing' and 'sourcing'.

There is a difference between the terms, 'purchasing' and 'sourcing'.

What is 'sourcing' and how does it differ from 'purchasing'?