Helpful means ready and useful in giving help. The person who notices you are struggling and does something about it.
It describes people and things equally, so a helpful colleague and a helpful diagram are both doing the same job. The word is warm and very common in British politeness, and its ironic use is common too, since that's helpful said flatly means the opposite. Its negative, unhelpful, is one of the mildest-sounding and sharpest criticisms in office English. The noun is help, and helpfulness is rare by comparison.
1adjectivehelpfulGiving or ready to give useful assistance.
“The woman at the desk was extremely helpful.”
Middle English
helpful
English, today
helpful
From Middle English helpful; equivalent to help + ful.
Etymology from Wiktionary, CC BY-SA