Hi  Nick and thanks for this essay

Introduction

On the one hand, people believe that politicians are the greatest impact on the world. On the other hand, insist that scientist’s affecting is the foremost on the current world. Following are my different views between politicians and scientists.

Your intro is a little too similar to the question. An IELTS examiner may penalize you by not including these sentences in the word count.

One thing you can do is use synonyms (instead of politicians, use “political figures” or “leaders” or “dictators, prime ministers, heads of government”). Another strategy is to change the tense. A third approach is to change statements into questions (or vice versa):

Who has had the biggest impact on our world? Has it been political figures, such as the presidents, prime ministers and other leaders who have led us into war and peace? Or has it been the scientists who have saved millions of lives, or invented weapons that could destroy the planet?

Your thesis sentence is a little weak. Why not give your opinion and say what you are going to do?

Following are my different views between politicians and scientists.

Here's a rewrite:

In this essay, I will explain why it is impossible to decide which group has had the bigger impact

Number of Ideas

You have two ideas in your second and third paragraphs. I think three is a magic number.  Think of the standard seven-sentence paragraph:

• The  topic sentence
• Idea 1
• Idea 1 example or more information
• Idea 2
• Idea 3 example or more information
• Idea 3
• Idea 3 example or more information

Usage/Word Choice

Obama, Bush, Regan all are the most remarkable role on the world. ==> Politicians such as Obama, Bush, and Reagan have a most remarkable role on the world stage.

Besides, they assist people to achieve their goal, hence argument economy. ==>  Besides, they help their citizens to become more prosperous and therefore improve the economy

His way of thinking and products, Apple, has inspired the human race in electrically research, mentally, and also physically  ==>   His way of thinking and his products, such as the Apple computer, the iPod and the iPhone, have inspired us and revolutionized computing, communication, and entertainment.

Finally, I strongly believe that politicians and scientists both are important on our present world.   ==> Finally, I strongly believe that politicians and scientists both are important in our world.

Technology and discipline is dispensable in a development city ==>  Scientific technology and leadership are both indispensable in a developed society.

Keep Sentences Short!

Addressing global problems and promoting urbanization cannot be expanded without scientists, such as infrastructure and the pace of life, these ideas should progress through the technology explosion.

That’s 27 words -  it’s a bit too long, and has some parts which could be left out:

Global problems cannot be addressed without scientists. Advances in technology and our improved lifestyles have all come about through the work of scientists. (23 words, average 11.5 word per sentence)

Run-On/Comma Splice

Be careful not to join separate sentences with a comma

Secondly, politicians can ask the government to create more job opportunity for unemployed workers, because of this, people believe that politicians outweigh scientists.

Here’s a rewrite:

Secondly, politicians can create job opportunities for unemployed workers. This increases their popularity, whereas scientists are largely unknown and unrecognized.

Here’s another:

Even so , in terms of scientists, as they discover numerous natural resources, people could have them to enhance life of effective, such as computer, the Internet.

Here’s a rewrite

As scientists discover natural resources and develop new technologies, people’s lives are enhanced. 

Thanks again.

Here's an easier paragraph -  again with 7 sentences (a topic sentence and three ideas, each with more information or an example). 

Scientists and politicians have always been closely related. First of all, politicians can claim scientific breakthroughs for themselves. When Russian scientists were the first to orbit the moon, the Soviet Union scored a huge political victory over the USA. Secondly, scientists need money from the politicians. Research such as the huge CERN collider under the French-Swiss border requires vast investment from many governments. In addition, sometimes scientists become political targets. Several researchers and scientists have been attacked or assassinated because of their work. 

Hello Radha and thanks for this essay. Some nice phrases and sentences and a clear layout.

I think some reorganization is needed in Para 2, but the main suggestion I would make is perhaps to replace the slightly over-the-top exaggeration in Paragraph 3 with some specific examples. Who are some of the famous scientists you describe?

Agreement

Both the groups have a  different kind of personalities → Both groups have different kind of personalities

Pronoun reference

The people of world had always admired them and surely many young scientists will be in the same position → Unclear pronoun reference.

Introduction

Your intro would be stronger with a thesis sentence. You could change your third sentence into a thesis sentence AND you could give your opinion

I will explain that although politicians may have more charisma, scientists are more respected.

Word Choice

• let me bring forth the influence of scientists among people →let us examine/look at/ focus on/analyze/discuss/
• gadgets and gizmos → in ten years, no one will be the word 'gizmo.' Yes, the IELTS descriptors look for 'less common lexical items with some awareness of style and collocation’  but the word gizmo is a buzz word, and is now dangerously overused.

Reorganize -  group related ideas

Your paragraph about politicians goes from plus to minus to plus. Why not keep all the plusses together? Here’s one possible reorganization with all the plus factors first and then the negative ones:

Firstly, many politicians are diplomatic, wise and charismatic. Some selfless politicians have even laid down their lives for the sake of their people. No Indian can forget the role of Mahatma Gandhi in Indian history. However, they can also be self-motivated and ruthless if they face any revolt. The surprising part is even the politicians with certain negative aspects also influence the masses. For example, in India politicians are like magicians. They lure the innocent villager as well the rich and intelligent industrialists with their sweet talk. Such is the influence of the politicians that the word 'politics' is itself dirty for some people. 

Usage/Verb tense

Be careful with the past perfect (e.g. ‘had been admired’) and try to avoid it unless one thing happened before another. It’s not standard usage.

Exaggeration/Generalization

You wrote:

Secondly, let me bring forth the influence of scientists among people. Unlike the politicians, scientists attract people for their useful contribution to the developing world. They are revered universally for their priceless invention of simple household gadgets and gizmos to complicated jet airplanes and nuclear weapons. Their names are written in golden letters in the world of science and will never be wiped out in the near future.The people of world had always admired them and surely many young scientists will be in the same position.Indian Ex- president Dr.Abdul Kalam is a good example of such people. 

In conclusion, although some people might feel that politicians attract the masses with their glitter of money and muscle power, I firmly believe that scientists are real heroes and are respected and idolized by people of the world for making this world a better place to live in.

Whoa!

I know what you mean, but don’t go over the top. Try to control your excitement: I doubt if most people could name more than a handful of scientists, so to say that they are ‘idolized’ or ‘revered’ or that their names are ‘written in golden letters’ is too much. 

What else could we say? Any ideas anyone, or should we just be boring and replace these terms with more, well, boring ones?