1. Processor: 64bit x86 with at least 2 cores.
2. Memory: Minimum 4 GB of RAM though more is recommended depending on the number of VMs.
3. Storage: 1 GB of local storage is required for installation.
4. Network: At least one Gigabit Ethernet network adapter ensures the hardware is listed on the VMware Compatibility Guide for optimal performance and support.

ESXi hosts can be managed using the vSphere Client, a web-based interface or through vCenter Server for paid editions which allows centralized management of multiple ESXi hosts and advanced features like vMotion, HA and Distributed Resource Scheduler.

vSphere ESXi 6 host maximum memory is 12 TB.

VMware ESXi discovers a robust bare metal hypervisor that installs directly onto your physical server with direct access to and control of underlying resources VMware ESXi effectively partitions hardware to consolidate applications and cut costs.

VMware vSphere Hypervisor ESXi is a bare metal hypervisor designed for deploying and serving as a virtualization layer for virtual machines (VMs). It abstracts and pools hardware resources to allow multiple VMs to run on a single physical server.