If you are rendering your component using JSX, the name of that component has to begin with a capital letter otherwise React will throw an error as unrecognized tag. This convention is because only HTML elements and SVG tags can begin with a lowercase letter.
class SomeComponent extends Component {
// Code goes here
}
You can define component class which name starts with lowercase letter, but when it's imported it should have capital letter. Here lowercase is fine:
class myComponent extends Component {
render() {
return <div />
}
}
export default myComponent
While when imported in another file it should start with capital letter:
import MyComponent from './MyComponent'