Special Economic Zones are areas which are notified to be located outside the domestic tariff areas . Which means that the firms located in SEZs can import anything of any value duty free but such firms must be net forex earners. It is a specifically defined geographical area in which the business and trade laws are different from rest of the country. SEZ are located within a country’s national borders. It that particular area government provides discount on tax.
The SEZ scheme was launched on 1st april 2000. Thereafter the Special economic zone act was enacted in 2005 and the rules were implemented from 10th February 2006. 
The major objectives of SEZ was to eliminate the discrimination between the economic stability of various states in the country . SEZ facilitates the increase in Foreign direct investment and increase in trade balance and increased trade and export within the country, leading to job creation and elimination of unemployment which is posing a major burden on the country . It will also lead to more investment by the foreign entrepreneurs because there will be less or minimal tax payment in these zones, hence leading to the complete development of the area. 
The SEZ act seeks to liberalise the policy of establishment of SEZ’s in the private sector . It established board of approval as a single window SEZ approval authority so that things go faster and smoother. Apart from being custom free firms will also get some tax rebates which means exemption from exercise service tax , central sale tax.
The country has seen as vast increase in the SEZs from the year of its establishment uptil now. In February 2006 there were 19 SEZs and in 2019 there are, as many as 239 SEZs . Also there is an increase in investment from 4 thousand crore to 4 lakh crore . There has also been a steep rise in the employment ratio over the past years . Drastic improvement reflects in the import sales of the country. So vast improvement can be seen in the past 10 years regarding the performance of SEZs in various fields and is benefitting the country in multiple ways possible.
Recently the SEZ (Amendment) Bill 2019 replaced an ordinance of March 2019, which amended the SEZ Act of 2005 to add two new categories - "trusts or any entity, as may be notified by the Central Government" - among those eligible for setting up units in the notified SEZs. These amendments will certainly bring some positive changes in the SEZs .
Looking at these statics and the growing conditions of the economy it can be concluded that the SEZs by now have proven to be a valuable asset to the country providing great opportunities for present as well as future. But there are still some glitches at hand that needs to be resolved such as lack of agricultural land as most of the land are used for the establishment of SEZs and also a proper system of rehabilitation should be established for the people who had been affected by the using up of lands . As development should never be on the cost of another lives and emotions .
So the Special Economic Zones are an useful aspect of our country to bring in powerful resources which will lead us to an developed nation , but there needs to be a proper management and utilization technique in use, and a balance must be maintained between the development and livelihood of people at stake.
Footnots  https://www.youtube.com/watch?v=hCWYVxjukA8.  https://commerce.gov.in/publications/pdf/CHAPTER_5.pdf.  http://sezindia.nic.in/cms/list-on-notified-sezs.php.  https://www.businesstoday.in/current/economy-politics/sez-amendment-bill-2019-sepecial-economic-zones-boost-economic-activities-employment/story/360856.html.
Author- Aeshna Raghuwanshi, Content writer, Legal Eagle.