, or occasionally は勿論（もちろん）, is a phrase in Japanese that presents (A) as being something obvious, while (B) should still be considered/mentioned. In this expression, the 副助詞（ふくじょし） (adverbial particle) は presents (A) as being a stand-alone topic, before the 副詞（ふくし） (adverb) もちろん ‘naturally’ emphasizes that (A) is what it is. After this, the (B) part of the sentence will describe some other factor that is worth mentioning.
will be used directly after noun (A), before the sentence will go on to discuss noun (B). This construction can be translated as ‘not only (A), but (B)’, ‘not to mention (A), (B)’, and other similar English expressions.
Please ask me anything, not only about computers but also other electronics.
We are looking for someone not only who can teach math, but every subject in this school by themselves.
In many cases, despite (A) being the obvious factor, (B) is being highlighted as sharing similar qualities to (A). This means that in はもちろん
sentences, も will almost always be seen after (B).
Not only can she speak Japanese, but she can also speak Korean.
This author is popular, not only because of his book, but also because he is a good singer.
While quite similar in meaning to だけでなく, はもちろん is quite a bit more formal. Due to this, it may sound quite stiff in friendly conversation, unless particularly emphasizing something.