noun
debut; first appearance; new release
Used for the first public appearance of a product, person, or work. Often seen in promotional contexts.
新登場のスマートフォンが話題になっている。
The newly released smartphone is getting a lot of attention.
彼女の新登場アルバムは来月発売される。
Her debut album will be released next month.
初登場 also means 'first appearance' but is more neutral and factual, while 新登場 carries a nuance of 'newly introduced' with a promotional tone.
Compound of 新 (new) and 登場 (appearance, entry). The word follows standard Sino-Japanese word formation.