The first head is the party in the electorate. This is who the supporters of your party are. They don't have to be actual members of the party, it's enough that they publicly speak that they support you and will vote for you and this is a huge amount of voters because these are the common people who don't deal with politics.
The second head is the party as an organization. This is the classic company like organization with staff, headquarters, laws and legislation, taxes, and similar things. The goal of the organization is to win the elections and they help on a state, national, and local level with things like campaigning and other important aspects of politics.
The third head is the party in government. These are party members who are members of the congress and although they may disagree with some party policies, they are in general the spokespeople for their party and represent it and its values. They are the people who vote on legislation and the budget and similar things.
Answer: The print revolution transformed Europe by promoting literacy and education and energizing: the renaissance, reformation, scientific revolution, and enlightenment.
