Example sentences
diàn电nǎo脑huài坏le了。
The computer broke.
shuí谁zài在yòng用diàn电nǎo脑？
Who is using the computer?
About this word
电 is "electric" and 脑 is "brain", so the machine is an "electric brain". 脑 appears in 大脑 the brain, 脑袋 head, 脑筋 wits. The word names the device by what it does rather than by how it works, and it is the term everyone uses in daily life. 计算机, "calculating machine", is the formal and technical label, the kind you see on a university department or in a legal document. Both are correct, and only register separates them. A laptop is 笔记本电脑, literally a "notebook computer".
The story behind the character
电
The bronze 电 is a bolt of lightning, zigzagging down. The traditional 電 added a 雨 (rain) on top but kept the lightning below. Xu Shen wrote 电, 阴阳激耀也. The electricity in your phone began as the bolt splitting the sky.
脑
脑 is 月 on the left, which here means flesh rather than moon, plus a squeezed shape on the right that started as a picture of a baby's soft spot. The old form 腦 kept more of it: 巛 for hair, 囟 for the fontanelle, the gap in a newborn's skull. Xu Shen defined the character as 頭髓也, the marrow inside the head. So 电脑, a computer, is head marrow made of electricity.