Execution context is a temporary runtime environment that initializes any external dependencies such as HTTP clients, database connection, SDK clients
The context is maintained for sometime as next invocation is anticipated, as it can reuse the context
Execution context includes /tmp directory max 10GB of disk-space. The tmp directory’s lifespan is around warm invokations
lambda’s temporary storage shouldn’t be used for persistence, for these you can go for s3, file systems or DBs
For encryption you must have to go with KMS data keys