Question on EF approach

Question

Hi Experts,

I have few Questions on EF. I know that we have 3 approaches in EF

i. Database approach

ii.Code -First Approach

iii.Model-First

So my questions are

1. If an application implemented using EF, so does the application must be followed in any of the above?

2. Let's take an example. I have an existing application called "USAPP" which implemented by using the code- first approach. I have created One more application "RussiaAPP" using the "USAPP" database with EF context classes. So can I say 2nd application "RussiaAPP" implemented by using the "Database First approach?

Thanks in Advance