Delta Lake is a data storage and management layer that fixes the issues with existing data lakes, e.g. on S3, GCS or ADLS. Delta supports streaming and batch operations. It's an open source project, donated to the Linux Foundation. You can check it out at https://delta.io/.
A lakehouse is a data architecture. It combines the best qualities of data warehouses & data lakes to provide a single solution from streaming analytics to BI, data science, and AI. A good starting point to learn more about the Lakehouse is this Lakehouse article at the Databricks blog.