The word 购物 (gòuwù) means "shopping" and functions as a verb or part of a compound noun. It is more formal than 买东西 and often appears in contexts like 购物中心 (shopping center) or 购物之旅 (shopping trip). Use it when describing the activity of shopping in general.
周末我们去购物吧,商场在打折。
Zhōumò wǒmen qù gòuwù ba, shāngchǎng zài dǎzhé.
Let's go shopping this weekend; the mall is having a sale.
她最喜欢在网上购物,方便又快。
Tā zuì xǐhuān zài wǎng shàng gòuwù, fāngbiàn yòu kuài.
She likes shopping online the most — it's convenient and fast.
这家购物中心里什么牌子都有。
Zhè jiā gòuwù zhōngxīn lǐ shénme páizi dōu yǒu.
This shopping center has every brand you can think of.