This is the 9473rd most frequent Japanese word.
第一生命保険
Dai-ichi Life Insurance Company.
Here, 第一生命保険 is used as a proper noun referring to the company name.
第一生命保険は日本の主要な生命保険会社の一つです。
Dai-Ichi Life Insurance is one of Japan's major life insurance companies.
In this sentence, 第一生命保険 refers specifically to the products offered by the company.
私は第一生命保険のプランについて詳しく知りたいです。
I want to learn more details about the Dai-Ichi Life Insurance plans.
Here, 第一生命保険 signifies the choice of the organization based on its characteristics.