What actually is Population of Data? I have just started my statistics journey and as part of assignment I was given one statement and had to deduce population, sample etc from it. The statement is as follows: 
A council wishes to study the digital awareness of its resident senior population (over 65 years), so it questioned in person 50 inhabitants randomly chosen from a database of the entire resident population. 
Now, as per defination, population is the entire group that you want to draw conclusions about. Here, I want to draw conclusion about Senior residents. But the sample is taken from entire resident population here (I think so because it is not clearly stated). So what is my population here,All senior residents in the country OR Be a resident of the county and belong to the database.
Also, would this lead to any sample biasing?

Population: All resident seniors(above age 65) in the country.
Sample: Resident Seniors recorded in the database.
Sample Bias: Only those seniors are included which are part of database. Therefore, resident seniors which are not on record are left out.
