We should always comply with the one file one component "policy"; that is, writing only one component in one file. This means that you should not have more than one component in a file. For example, this is considered bad practice:
// .js
Vue.component('PostList', { ... })
Vue.component('PostItem', { ... })
They should be split into multiple files, as follows:
components/
|- PostList.js
|- PostItem.js
This should be done as follows if you are writing the components in .vue:
components/
|- PostList.vue
|- PostItem.vue
