My parents smack my little brother sometimes but people at school say it is wrong, is it?
Smacking is an issue of hot debate.
And in different countries the rules are different so not knowing where you are from no specific information can be given.
Historically of course smacking was common place and probably the vast majority of parents did it.
In recent years there has been more pressure to ban smacking however in a lot of countries moderate or light smacking is still perfectly legal and therefore in the legal sense parents aren't doing anything wrong for gentle smacking.
However there are many other forms of punishment such as being grounded, having pocket money withdrawn and so on and the individual merits of smacking are debated.
There are lots of websites that offer more information on this, but if your parents decide to use smacking and it is legal in your country then there is little you can do but to respect their wishes even if you find the idea horrible yourself.
If it upsets you then tell your parents how it makes you feel and why you think it is wrong and it may make them change how they behave.