Indicates a medium, means, or intermediary by which something happens or is communicated. Often used with nouns like インターネット, 友人, or 経験.
インターネットを通じて世界中の人とつながれる。
You can connect with people all over the world through the internet.
throughout; all through; all over
Describes something happening continuously over a period of time or across an entire area. Common with time nouns like 一年 or 一生, and location nouns like 全国.
I got to know her through a friend.
In this region, a mild climate continues throughout the year.
その歌手は全国を通じて人気がある。
The singer is popular all over the country.