银子 means "silver" and refers to the precious metal historically used as currency and in trade. Like 金子, the suffix 子 gives it a colloquial tone. In historical contexts, 银子 often refers to silver money or silver taels used in ancient China.
以前的人用银子买东西。
yǐqián de rén yòng yínzi mǎi dōngxi.
People in the past used silver to buy things.
这个手镯是银子打的。
zhège shǒuzhuó shì yínzi dǎ de.
This bracelet is made of silver.
在古代中国,银子是主要的货币。
zài gǔdài zhōngguó, yínzi shì zhǔyào de huòbì.
In ancient China, silver was the main currency.