Hi BamaGal1,
Thanks for contacting Apple Support Communities!
We understand that you'd like to know the difference between Cellular and Cellular Data in your iPhone Settings.
The Cellular Settings typically pertain to making and receiving calls and Cellular Data allows you to use your apps with a cellular connection rather than a Wi-Fi connection. The options you see within your Cellular Settings can vary based on the features that your cellular carrier provides. This is a handy resource which explains the options in more detail: View or change cellular data settings on iPhone - Apple Support
Set cellular data use for apps and services
Go to Settings 
> Cellular, then turn Cellular Data on or off for any app (such as Maps) or service (such as Wi-Fi Assist) that can use cellular data.
If a setting is off, iPhone uses only Wi-Fi for that service.
Note: Wi-Fi Assist is on by default. If Wi-Fi connectivity is poor, Wi-Fi Assist automatically switches to cellular data to boost the signal. Because you stay connected to the internet over cellular when you have a poor Wi-Fi connection, you might use more cellular data, which may incur additional charges depending on your data plan. See the Apple Support article About Wi-Fi Assist.
If your Apple Watch includes a cellular plan as well, you can use your Apple Watch to make calls and use Messages and more, if you choose to, without your iPhone. You can learn more about the features that are available on your Apple Watch if you don't have access to your iPhone here: Use your Apple Watch without your iPhone nearby - Apple Support
If your Apple Watch is connected to Wi-Fi or cellular
With a Wi-Fi or cellular connection, your Apple Watch can do the following things, even if your iPhone isn't with you.
Make and answer phone calls.1
Send and receive messages.2
Use Siri to get directions, send iMessages, and more.
Check the weather.
Track your stocks.
Control your home.
Find your friends, devices, and items.
Set reminders.
Listen to podcasts.
Use Walkie-Talkie.
Stream music.
Find your way with Maps.
Send and read email.
Read top news stories.
We hope this helps.
Cheers!
