VM series naming (D, E, F, B and s/a/p)
Azure size names encode family, vCPU count, features, and generation — e.g. Standard_D4as_v6.
An Azure size name packs several facts. The family letter sets the category: D = general purpose, E = memory optimized, F = compute optimized, B = burstable. The number is the vCPU count. Lowercase feature letters follow: s = premium storage, a = AMD, p = Arm (Cobalt or Ampere), l = lower memory. The _vN suffix is the generation.
So Standard_D4as_v6 is a 4-vCPU, general-purpose, premium-storage, AMD, v6 VM. Standard_E8ps_v6 is an 8-vCPU, memory-optimized, Arm, premium-storage, v6 VM.
More Azure pricing terms
On-Demand (Pay-As-You-Go)Reserved VM Instance (RI)Savings Plan for ComputeAzure Hybrid Benefit (AHB)Spot Virtual MachinesSpot eviction & eviction policyDev/Test pricingARM region nameMeter & SKUConstrained-vCPU sizesB-series burstable & CPU creditsEphemeral OS diskCobalt & Ampere (Arm on Azure)vCPUEffective hourly rateWindows vs Linux pricingMax saving %Best price regionNormalized pricing ($/vCPU, $/GB)