Can I use same Gmail account for iPad & Android and still work separately?

not sure what you mean by "work separately"

if you mean that you can delete a mail from one of them and it will stay on the other then, not unless

google still offer the old pop3 mail account

all modern email providers these days rely on IMAP or Exchange where everything is handled server side and all clients view the same server content

you can read about it here What is IMAP & POP3? And should you choose IMAP or POP3?

you can read about using pop3 with gmail here Read Gmail messages on other email clients using POP - Gmail Help

Perhaps you refer to your Gmail address being used for your AppleID - now known as your Apple Account. The email address that you use to identify your Apple Account is merely an identifier - and has no direct impact upon your email.

If instead you are concerned about accessing your email, you can access your mailbox from multiple computers/devices - such as your mobile phone (iPhone or Android), iPad, Mac computer, Windows PC or from a web browser. Your mail messages will be accessible from and automatically synchronised between your devices - unless (as mentioned by Rudegar) you are using a very old POP3 mailbox account, which is perhaps very unlikely.

Adding and email account to your iPad and iPhone is trivial. Simple follow the guided steps for adding the account via your device settings:

Settings > Mail > Add Account

Be aware that some email providers now require the use of App Specific Passwords when accessing mail over IMAP or POP3. If this applies to your email account, you will need to generate a unique password for your iPad email account - that will differ from your normal Account Password. As examples - AOL, Yahoo and Microsoft all use App Specific Passwords when using anything other than their own email client Apps.

If you need to generate an App Specific Password, you’ll need to log-in to your Mail Providers account management webpage - using a web browser - and generate the Password from the appropriate account security page.

More information about AOL’s App Specific Passwords can be found here:

https://help.aol.com/articles/allow-apps-that-use-less-secure-sign-in?guccounter=1

For Yahoo, more information can be found here:

https://help.yahoo.com/kb/SLN27791.html

Microsoft:

https://support.microsoft.com/en-us/account-billing/using-app-passwords-with-apps-that-don-t-support-two-step-verification-5896ed9b-4263-e681-128a-a6f2979a7944

If using Gmail (Google Mail), Google have recently required that your Mail client uses OAuth to authenticate. If applicable, simply deleting and re-adding your Gmail account through iPad Mail Account settings should resolve any issues.

ailene257 wrote:

sorry what i mean is if use whats app or download an app on my samsung idont want it to show up on the ipad

The Android and Apple App Stores are entirely independent. Purchasing and downloading an App for your Samsung (Android) device will have absolutely no impact upon your Apple devices. Similarly, any Apps that you install on your Apple devices will have absolutely no impact upon your Samsung.

That said, accessing the same email account from either device will allow you to see and manage the same email account from either device.

that would have nothing to do with email accounts at all

no, if you use the same appleID email account on several different devices it will not mean they will download the same apps as each other. if you have an iPad and an iPhone it will by default do so but you can disable that

but if you use the same email account on say an iPad, an android device and a windows computer they will not auto install apps released for all devices if you download an app from one of them