What is the main difference between a formal and informal qualifications for the house of representatives

The question is asking to states the formal and informal qualifications. The answer would be the following: 
(FORMAL QUALIFICATIONS)

1. Must be at least 25 years of age
2. must be a citizen of U.S. for at least 7 years.
3. must be inhabitant of the Senate from which you are elected. 

(INFORMAL QUALIFICATIONS)
These have to do with a candidate's vote-getting abilities 

1. Party identifications
2. Name familiarity
3. Gender
4. Ethnic Characteristics
5.Political experience