Wi-Fi is a way for phones, computers and other machines to join a network — usually the internet — through radio waves in the air, with no wire going into the machine.

Wi-Fi is a way for phones, computers and other machines to join a networkWi-Fi是讓手機、電腦和其他機器加入網路的一種方式 — usually the internet通常是網際網路 — through radio waves in the air靠空氣中的無線電波，with no wire going into the machine機器不用接任何電線。

In everyday talk it has three slightly different jobs. First, it means the technology itself: "This machine has Wi-Fi." Second, and much more often, it means one particular connection in one particular place: "The Wi-Fi here is slow", "What's the Wi-Fi password?", "Is there free Wi-Fi?" Third, people use it to mean the internet in general, which is not strictly correct but is completely normal speech: "The Wi-Fi is down" often really means the internet line outside the building has a problem, not the radio part.

In everyday talk在日常說話裡 it has three slightly different jobs它有三個稍微不同的用法。First首先，it means the technology itself它指這項技術本身："This machine has Wi-Fi."「This machine has Wi-Fi.」Second, and much more often第二，而且更常見，it means one particular connection in one particular place它指某個地方的某一個連線："The Wi-Fi here is slow", "What's the Wi-Fi password?", "Is there free Wi-Fi?"「The Wi-Fi here is slow」、「What's the Wi-Fi password?」、「Is there free Wi-Fi?」Third第三，people use it to mean the internet in general人們用它泛指網路整體，which is not strictly correct but is completely normal speech這在嚴格意義上不算正確，但完全是正常的口語："The Wi-Fi is down" often really means the internet line outside the building has a problem「The Wi-Fi is down」通常其實是說建築物外面的網路線出了問題，not the radio part不是無線電的部分。

It is an uncountable noun, so we say "some Wi-Fi" or "the Wi-Fi", never "a Wi-Fi" or "two Wi-Fis", though the plural does show up in casual writing about hotels comparing networks.

It is an uncountable noun它是不可數名詞，so we say "some Wi-Fi" or "the Wi-Fi"所以我們說「some Wi-Fi」或「the Wi-Fi」，never "a Wi-Fi" or "two Wi-Fis"不會說「a Wi-Fi」或「two Wi-Fis」，though the plural does show up in casual writing about hotels comparing networks不過在比較各家旅館網路的輕鬆文章裡，還是會看到複數形式出現。

The word is neutral in tone — engineers write it in technical papers and children shout it at their parents. You will see it written Wi-Fi, WiFi, wifi and wi-fi; the company that owns the name insists on Wi-Fi, but nobody will correct you.

The word is neutral in tone這個字語氣中性 — engineers write it in technical papers工程師會寫在技術論文裡 and children shout it at their parents小孩也會對著爸媽大喊。You will see it written Wi-Fi, WiFi, wifi and wi-fi你會看到它被寫成Wi-Fi、WiFi、wifi和wi-fi；the company that owns the name insists on Wi-Fi擁有這個名字的公司堅持要寫Wi-Fi，but nobody will correct you但沒有人會糾正你。

As a verb it is rare and only very informal, meaning to give a place a Wi-Fi connection.

As a verb it is rare and only very informal當動詞用很少見，而且非常口語，meaning to give a place a Wi-Fi connection意思是讓一個地方有Wi-Fi連線。

One thing worth knowing: Wi-Fi only carries the signal the last short distance, from a box in the room to your phone. That is why your phone can show a strong Wi-Fi sign and still load nothing — the box is close and healthy, but the line from the box to the outside world is broken.

One thing worth knowing有一件事值得知道：Wi-Fi only carries the signal the last short distanceWi-Fi只負責訊號最後一小段距離，from a box in the room to your phone從房間裡的那個盒子到你的手機。That is why your phone can show a strong Wi-Fi sign and still load nothing這就是為什麼你的手機可能顯示Wi-Fi訊號很強，卻還是打不開任何東西 — the box is close and healthy盒子很近也很正常，but the line from the box to the outside world is broken但從盒子到外面世界的線路斷了。