Crawling versus Indexing Filter

(from github.com/dankoh)
Hi,

can you please define the difference between the indexing and crawling excluded path option?

.*\/_general\/.*\.(?i)(pdf|txt|rtf|docx|doc|xlsx|xlsm|xltx|xltm|xls|pptx|pptm|ppt|potx|potm|ppam|ppsx|ppsm|sldx|msg|eml|mpp|htm|html)

Adding this regex to the crawling option does not check subdirectories of general at all, adding the regex to the excluded paths for indexing works though but creates a huge amount of unneccesarily crawled files.

(from github.com/marevol)
Excluded URLs For Crawling does not crawl and index URLs.
Excluded URLs For Indexing does not index URLs, but crawls them.