Difference Between SGML and XML (With Table)

Designing a responsive and user-friendly website is not an easy task. It requires lots of effort, and you need the correct language to use. The two famous languages used in website design are SGML, and the other one is XML. They have got separate features and have both advantages and disadvantages. XML is also derived from SGML. But it has some amazing features. 

SGML vs XML

The main difference between SGML and XML is that a meta language will be used in SGML. But markup language will be used in XML. SGML will not allow its user to use data validation. But XML will allow you to use data validation. SGML will be very difficult to code and needs special software. XML will not be that much difficult to code and needs separate software. 

SGML is a markup language used by IT people. It is popular among markup languages. It is an extension of the HTML language. But the features, coding part, and stylesheets used in SGML are entirely different from HTML. The subset language of SGML is XML. The subset was first designed for the worldwide web, but now it is used in unrelated areas. 

XML is a language used in the back of HTML for simplifying the creation of large websites. It does not come under any programming language type as it has no separate vocabulary and grammar rules to perform them. You can store the XML in a simple text file. For interpreting XML, you need to have special software. It will not be replaced with HTML, but it has got some new features that can be used alongside HTML.

Comparison Table Between SGML and XML

Parameters of Comparison

SGML

XML

Language

It is a meta-language

It is a markup language

Features

It has complex and also requires overhead to use it

It does not have complex and overhead for use

Data Validation

It does not allow data validation

It allows data validation

Datatag declaration

It is allowed in SGML

It is not allowed in XML

Empty start tags

They are allowed in SGML

They are not allowed in XML

What is SGML?

SGML is an expansion of Standard Generalized Markup Language. HTML is an application that is used in SGML. It is used for marking up documents. It is independent and now dependent on any specific application. SGML is derived from GML, which is nothing but Generalized Markup Language. With the help of this, users can work on standardizing different formatting styles for their electronic documents. It is unique because you can write your markup schemes.

SGML consists of three main components such as SGML declaration, document instance, and Prolog. SGML helps you to encode the full structure of the document. Also, it supports any media type. It would be a good use of HTML as it has the capability of visual code representation. It can separate the content from appearance. It allows for more complex formatting. This feature is not available in SGML. That is the main reason why many people prefer SGML over HTML.

SGML contains stylesheets that help to make the content used for different purposes. It is extremely flexible. Because of the ISO standard, it has got many well-supported tools. However, it has got some disadvantages as well. Nothing comes with full advantage. To code in SGML will be very typical and difficult as well. SGML tools are always expensive. For displaying the document, you need to have some special software installed in your system. 

What is XML?

The expansion of XML is an extensible markup language. The reason why it is created is that for storing and transporting data. It is very similar to the HTML language. It is used for representing documents, books, invoices, transactions, and many other things. It is also used in asp.net for ad rotator and some other features. The XML language has many uses, and it is incorporated in building many websites. 

It is derived from an old standard format of SGML for making web pages more responsive. Many people call this a cousin to HTML. It helps to conduct complex business over the internet. It is extensible, which means you can create your stages and language for your application. It is used to carry the data and will not present it. You can store the data irrespective of how the data is being presented. It was developed by the world wide web consortium. Therefore, it is an open standard. 

You can customize your data handling needs with the help of XML, as it allows you to store and arrange the data. For creating any desired or specific output, you can always merge them with the stylesheet. You can also express any type of data in the XML document. For reloading and offloading databases, you can use XML. You can easily exchange information between the organization and systems. It will work behind the HTML and make the website more attractive and responsive. 

Main Differences Between SGML and XML

  1. The language used in SGML is meta language. On the other hand, the language used in XML is a markup language.
  2. SGML has complex and overhead features which allow you to use them. On the other hand, you cannot find these features in XML, and it will not allow the user to use them.
  3. SGML will not allow the user to use data validation. On the other hand, XML allows the user to use data validation.
  4. Datatag declaration can be used in SGML. On the other hand, Datatag declaration cannot be used in XML.
  5. Empty start tags are used in SGML. On the other hand, empty start tags are not used in XML. 
  6. SGML stands for Standard Generalized Markup Language. On the other hand, XML stands for eXtensible Markup Language.

Conclusion

Both these languages are used by website designers as they will make the website more responsive and attractive. XML has cool features, and that is why many people prefer them using HTML as it will help in building large websites. When we build any large website, there will be lots of coding involved, and the stylesheet is also an important part.

All these stylesheets and coding simplification will be done with the help of XML. It is not going to replace HTML in the future. But it will be used in many projects because of the code simplification and further features involved in it, which are lacked by HTML. Regarding the rate, SGML is higher. But XML is open-source. 

References

  1. http://www.idea2ic.com/File_Formats/Comparison%20of%20SGML%20and%20XML.pdf
  2. https://books.google.com/bookshl=en&lr=&id=djqcBgAAQBAJ&oi=fnd&pg=PA3&dq=Difference+Between+SGML+and+XML&ots=B5H2UIPraH&sig=0Lt6iI6_siuaLLP9PJHdno679lY