# Storage

Learn how the SDK persists the visitor session.

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Use the summary below to quickly jump to a specific topic:

- [IdentityStore](/reference/sdk/php/api/storage/identity-store): Learn how the SDK persists the visitor session.
- [CookieStorage](/reference/sdk/php/api/storage/cookie-storage): Learn how to persist the visitor session in cookies.
- [InMemoryIdentityStore](/reference/sdk/php/api/storage/in-memory-identity-store): Learn how to keep the visitor session in memory.
- [CookieConfiguration](/reference/sdk/php/api/storage/cookie-configuration): Discover how to customize the Croct session cookies.
- [Cookie](/reference/sdk/php/api/storage/cookie): Discover the framework-neutral cookie returned by the storage.
- [Uuid](/reference/sdk/php/api/storage/uuid): Discover how the SDK represents universally unique identifiers.