What is the Vue lifecycle and why is it important?

The Vue lifecycle refers to the series of stages a Vue instance goes through from creation to destruction. Understanding the lifecycle hooks allows developers to execute code at specific points in a component's life, such as before it renders or after it updates.

Key stages include:

1. Creation: beforeCreate, created
2. Mounting: beforeMount, mounted
3. Updating: beforeUpdate, updated
4. Destruction: beforeDestroy, destroyed

For example, you might want to fetch data when a component mounts:

mounted() {
  // Fetch data from an API here
}