Apple / iOS / IPA / APP corporate signature are in fact the same meaning, Apple installation package is packaged with a process Enterprise, can provide only IPA format installation package signature operation, can also be packaged directly through the Xcode source code .
Apple Corporate Account (Apple Developer Enterprise Program) is available to Apple iOS developers a high-level developer account, the account is different from individual developers and corporate developers accounts, corporate accounts have the following characteristics:
price than the personal account and company accounts more expensive, $ 299 / year
can not submit the application to the App store store
can be signed application installed on any iOS device, and there is no limit to the number installed
where it is due to the characteristics of Article 3, to developers when testing and distributing App, brought great convenience. Therefore, the general application developers to use Apple's corporate account (corporate signature or Apple), but also for this feature. 
Note the use of company accounts
because Apple for App installation has a very strict limitations, so the use of the Apple account also gives companies the strict terms of use, see: Apple Developer - Terms and Agreements. One of the most important provisions are:
application of the use of corporate accounts signatures can only be used for internal staff to install, not for public download.
p12 certificate file and Provisioning Profile file not free to import and export, the best plane so that someone
their own developer account must not borrow
Do not upload the certificate file and Provisioning Profiles p12 file to a third-party package platform, compiler clouds, cloud platform test package like the best time in the enterprise network, if the Internet connection is required, please pay attention to the network environment not happen too big change internet telephony VOIP, integral wall, games, and other types of prepaid platforms are likely to be Apple's App title. 
Corporate Account Application
At present, the company apply for a new account through Apple's official website, it is very difficult. The reason is that, on the one hand when applying for business account, developers need to provide a lot of information needs to apples; on the other hand, Apple is the number of new business accounts for approval is also very limited. Therefore, the current stock of corporate accounts in the market is minimal. Therefore, this also leads to a lot of developers really need Apple's corporate account, can not apply for a business account. If any questions about Apple corporate signature / account can be used in comments below, you will see the return will be 11!