Propaganda is power to spread information to help or hurt a cause. It tells only the side you want people to know. It is generally carried out through media that is capable of reaching a large number of people and effectively persuading them for or against a cause. It is aimed to change public opinion. Often used in advertising when a famous person endorses a product, person or idea. For example if you use this perfume/aftershave, you will become more popular or this suit will make you look rich. Ideology is a set of aims and ideas.
An ideology can be a comprehensive vision, as a way of looking at things, or a set of ideas proposed by the dominant class of a society to all members of this society. The main purpose behind an ideology is to offer change in society. Ideology tends to refer to the way in which people think about the world and their ideal concept of how to live in the world. Ideology also may be used to describe the shared beliefs of a group of people.
Propaganda is based on an ideology. It does not exist without an ideology.Propaganda is the way to make people aware of ideological belief. An ideology is a set of thoughts and can reach people only through propaganda. Its content could be partly true and partly false. It can survive on its own; probably it would not be as widespread as it would be with propaganda. It is really important to understand and be able to distinguish between two, because they lead our day to day life.
A family, smallest unit of society follows an ideology. A child or an adult tries to live in those boundaries.Moment one tries to step out of it, it give birth to conflicts, disagreements or controversies. Similarly a society is derived by a set of ideology and every member tries to follow it. But at same time we should be capable to understand which ideology is just based on propaganda.
When an ad promises that this cream will give your healthy, clear and glowing skin in 60days, it is partly true and partly false. Truth is that it might improve your skin by moisturizing it, but we should use our commonsense that clear and glowing skin might be a false propaganda.