unknown is safer than any.
It forces you to validate the type before using it.
const response: any = await fetchData();
response.toUpperCase(); // may crashconst response: unknown = await fetchData();
if (typeof response === "string") {
response.toUpperCase(); // safe
}Type guards tell TypeScript what the value really is.
Frontend validation improves user experience. It shows instant errors and prevents obvious mistakes like empty fields or invalid email formats. But frontend validation is never security. Anyone can bypass it using DevTools, Postman, or by directly calling your API. That’s why backend validation is mandatory it protects your database and business logic from invalid or malicious data.
Before mastering Flexbox or Grid, you must understand how CSS calculates size.