Direct Attached Storage (DAS) arrays are directly connected to a single server or small group of servers. They are practical, cost-effective, and ideal for small businesses or individual workstations requiring basic storage expansion. DAS offers the same high capacity potential as SAN storage, but tends to have less advanced controllers, and does not allow for as many feature sets, making DAS storage typically the more budget-friendly option.

Storage Area Network (SAN) storage is known for high I/O processing speeds and low latency, making them ideal for high-speed transactional environments. SAN is centralized storage accessible by multiple servers over a dedicated network, and is ideal when shared storage and high availability is the priority.

Many Dell PowerVault series contain models that will act as either SAN or DAS storage, meaning they can be connected either directly to a single server, or as part of a multi-server dedicated storage network. These solutions enable the advanced feature sets of SANs, or the high performance and low latency of a direct server connection.

The Dell PowerVault MD3 series and ME4/ME5 series devices are both great candidates in the realm of storage solutions, each with its own set of features to meet different business needs and technological environments.

The MD3 series is Dell's flagship storage line from a couple generations back and still uses industry standard technology. They are great candidates for small to medium-sized businesses that require straightforward, cost-effective storage and expansion. It uses SAS (Serial Attached SCSI), iSCSI and Fiber connections to attach to servers, offering reliable performance and data protection. The MD3 series focuses on ease of scalability by adding more enclosures and provides options like SSD caching to boost read/write speeds, making it an excellent choice for businesses looking to enhance their server storage without complex network requirements.

The Dell PowerVault ME series is Dell's newest line of storage, built to address both entry-level SAN (Storage Area Network) and DAS needs, offering a more cutting edge and flexible storage solution. The ME series supports multiple connectivity options, including iSCSI and Fiber Channel, allowing it to integrate seamlessly into various network storage environments. This series comes equipped with advanced features such as thin provisioning, snapshots, replication, and data deduplication, which enhance data management and storage efficiency. The ME series is designed for businesses that need scalable, high-performance storage with robust data management capabilities, catering to a broader range of applications and workloads.