So far as I understand, both abstract techniques and pure virtual functions don't provide any functionality ... So are we able to say they are both same factor ?

Also, suppose a category (not always declared as abstract) consists of numerous implemented techniques (not abstract or virtual), but consists of a pure virtual function. Is class then abstract ?

Yes, those are the same factor. In C++, an abstract technique is yet another method of explaining the qualities of the pure virtual function. Both just mean a technique without any implementation provided that should be implemented inside a sub-class prior to the class can really be instantiated.

The problem completely with virtual functions and abstract classes in C++ is comparable because they basically mean the identical factor. Any abstract class should have a minimum of 1 pure virtual function otherwise it may be instantiated and would not be abstract. Likewise, any class with a minimum of 1 pure virtual function should be abstract because it must be extended to ensure that method can really be implemented.

Therefore, a category is abstract if and only when it consists of a minimum of 1 pure virtual function/abstract method.

Afterwards, languages like Java and C# made such things as this more explicit, permitting a unique keyword to define a category abstract as opposed to the presence of the pure-virtual function. C++ allows you need to do exactly the same things because these languages, but they are somewhat more explicit about this. :D

You do not clearly declare classes or techniques as abstract in C++. The existence of pure virtual techniques is the reason why them abstract.

I'd say yes, abstract techniques and pure virtual functions are conceptually exactly the same factor.

Also, suppose a category (not always declared as abstract) consists of numerous implemented techniques (not abstract or virtual), but consists of a pure virtual function. Is class then abstract ?

A category with a minimum of 1 pure virtual function is known as an abstract class.

In C++, a pure virtual member function results in the attaching type becoming an "abstract type".

Functions themselves can't be abstract, although the term is often misused in this way.

Yes, abstract techniques would be the identical factor as pure virtual functions the terms are frequently used interchangeably. IMO, "Pure virtual function" may be the C++ technically correct term which particularly denotes the truth that the function is placed to :

class myClass 

An abstract class is based on:

a category that's made to be particularly used like a base class. An abstract class consists of a minumum of one pure virtual function.

So essentially, an abstract class is definitely an abstract class since it is designed to become a base class (some base classes obviously must have implementable techniques which will have to be pure virtual). These classes become abstract classes by simply how they are utilised and extended from. Unlike languages like Java, there's no abstract or interface keyword modifier making this why we want a "verbal contract" to discuss abstract classes in C++.