If you've been modifying the pipeline, vocabulary, vectors and entities, or made
updates to the component models, you'll eventually want to **save your
progress** – for example, everything that's in your `nlp` object. This means
you'll have to translate its contents and structure into a format that can be
saved, like a file or a byte string. This process is called serialization. spaCy
comes with **built-in serialization methods** and supports the
[Pickle protocol](https://www.diveinto.org/python3/serializing.html#dump).

> #### What's pickle?
>
> Pickle is Python's built-in object persistence system. It lets you transfer
> arbitrary Python objects between processes. This is usually used to load an
> object to and from disk, but it's also used for distributed computing, e.g.
> with
> [PySpark](https://spark.apache.org/docs/0.9.0/python-programming-guide.html)
> or [Dask](https://dask.org). When you unpickle an object, you're agreeing to
> execute whatever code it contains. It's like calling `eval()` on a string – so
> don't unpickle objects from untrusted sources.

All container classes, i.e. [`Language`](/api/language) (`nlp`),
[`Doc`](/api/doc), [`Vocab`](/api/vocab) and [`StringStore`](/api/stringstore)
have the following methods available:

| Method       | Returns | Example                  |
| ------------ | ------- | ------------------------ |
| `to_bytes`   | bytes   | `data = nlp.to_bytes()`  |
| `from_bytes` | object  | `nlp.from_bytes(data)`   |
| `to_disk`    | -       | `nlp.to_disk("/path")`   |
| `from_disk`  | object  | `nlp.from_disk("/path")` |