noun
writing ability; writing skill
Refers to the skill of composing clear, effective, or persuasive written text, often in an academic, professional, or creative context.
文章力を上げるには、たくさん読んでたくさん書くことが大切だ。
To improve your writing ability, it's important to read a lot and write a lot.
彼は文章力があるので、報告書の作成を任されている。
He has good writing skills, so he's entrusted with writing reports.
文才 refers more to literary talent or a natural gift for writing, whereas 文章力 is a broader term for practical writing skill.
Compound of 文章 (writing, composition) and 力 (power, ability). The exact historical derivation is uncertain, but the word is a straightforward modern formation.