Public television or public broadcasting refers to noncommercial1 television that provides educational2 programs. Public television's funds3 can come from viewers through donations4 or national funding sources.
公共電視指的是提供教育性節目的非商業性電視台，公共電視的資金可以來自觀眾捐贈或者國家補助。

There is no standard5 definition of what public television is. But one of the key characteristics of public television is its aim to improve society by informing6 viewers. In contrast7, the goal of commercial networks is to produce popular shows to the audience.
  何謂公共電視並沒有一個標準的定義。但是其中一個重要的特色是，公共電視想藉由提供觀眾資訊以改善社會的目標。相對地，商業電視台的目的是製造流行的節目給觀眾。

The BBC8 (British Broadcasting Corporation) is one of the most famous public broadcasters9 in the world.  Since public broadcasting is free of commercial advertising, the quality of the programming is expected to be higher. Many people think that the BBC's news programs are more neutral10. 
英國廣播公司是世界上最知名的公共電視之一。由於公共電視沒有商業廣告，它的節目品質被期許會比較高，因此許多人便認為BBC的新聞節目比較中立。

In the United States, public television operates11 on a viewer-supported basis and with commercial sponsors of some shows. However, advertisements on public TV are usually shorter.
在美國，公共電視是由觀眾捐贈和廣告商贊助一些節目來經營的；但是，公共電視上的廣告多半比較短。

There are different public television systems in the world. But there is one thing in common: public broadcasters are all trying to provide better programs to viewers.
世界上有許多不同的公共電視系統，但是都有一個共同點：那就是所有的公共電視都想供觀眾更好的節目。

單字精解
1.noncommercial 非商業的
2.educational 教育的
3.fund 資金
4.donation 捐款
5.standard 標準的
6.inform 告知
7.contrast 對比
8.BBC（British Broadcasting Corporation ）  英國廣播公司
9.broadcaster 廣播公司
10.neutral 中立的
11.operate 作