Explanation:

Political parties, in the strict sense of the term, are associations of individuals sharing common values and preferences. They are organised on ideological lines and present a vision for the future. They have well trained cadres who are engaged in continuous political mobilisation of the masses. They use all the political means available to capture the power and consolidate their position to attain or realise their ideological goals. In a broader sense they are also interest groups. They have a social base whose interests it must protect and promote. They may adopt pragmatic approach and operate only in the immediate context. They may, sometimes, degenerate to the level of a pressure group to extract benefits for their group. In such a situation the distinction between a pressure group and political party may even disappear.
The pressure groups unlike the political parties are formed to solve their immediate problems. They are relatively more temporary than political parties. A pressure group may appear for a short time if it does not present any long-range programme. However, where the interests of the group are of long-range, the pressure group may also last longer. In such cases it may even project the sectarian interests as general or universal interests. It depends on the imagination of their leadership. The pressure groups may have a well-knit organisation and organised membership. Generally they do not have cadres and do not directly deal with people. In most of the cases they deal either with the political parties or governmental apparatus. The pressure groups have far greater flexibility compared to political parties as they do not go to people and stake their claims for power. It is precisely this process that distinguishes political parties from pressure groups.