大家常常听到Private Cloud和On-Premise两个术语，下面通过相关背景介绍区分两者的差别
Private Cloud定义
维基百科云计算 词条中解释了Private Cloud，其含义为“Private cloud is cloud infrastructure operated solely for a single organization, whether managed internally or by a third-party, and hosted either internally or externally”，其关键是只为单一组织运作。
On-premises Software定义
维基百科On-premises Software 是指安装在个人和组织机器里面的软件，对应的off-premises software通常是指“software as a service” ("SaaS") or “cloud computing”，其中强调“on the premises (in the building) ”是指自有。
Private Cloud类型细分
2类Private Cloud，分别为On-Premise和Hosted：
On-Premise Private Cloud, often called Internal Cloud, is hosted within an organizations own offices, or data center, and provides an internal solution for hosting needs.
A hosted Private Cloud solution is owned and operated by third-party service providers.
总结
从话术来看，公有云厂家站在卖服务的立场，更愿意把Private Cloud叫做“专有云”，其实就是Hosted Private Cloud，并希望为该组织提供第三方的运维服务。
而传统的设备厂家和软件厂家，更喜欢把Private Cloud叫做“私有云”，On-Premise Private Cloud，从而在强调“自有”的基础上更好的卖软件和硬件。
所以，oracle把本地软件下载，称为： On-Premises Server Releases，而把云上的软件介质称为：Oracle Public Cloud Releases，
本地的EXATDATA的软件介质为：On-Premises Engineered Systems。
