网民(wǎng mín) - internet user in Mandarin

网民 (wǎng mín) is an internet user, or netizen, from 网 (wǎng, net) and 民 (mín, the people, citizens), the same 民 (mín) found in 人民 (rén mín), the people, and 公民 (gōng mín), citizen. It treats internet users as a kind of population, which is exactly how it gets used in Chinese news reporting.

That collective, headline register is where 网民 (wǎng mín) shows up most: 网民对这个决定表示不满 (wǎng mín duì zhège jué dìng biǎo shì bù mǎn), "netizens expressed dissatisfaction with the decision", is the kind of sentence a news article opens with, summarising a mass of online reactions rather than naming one person.

It differs from 网友 (wǎng yǒu), which usually points at an individual online friend or acquaintance rather than internet users as a group. A single sentence can use both correctly for different reasons, but swapping one for the other tends to make a sentence sound like it is describing the wrong scale, one person versus a whole population.