retrospection: n. Review or recall; corroborate (past facts, etc).
introspection: n. Introspection, introspection.

retrospection and introspection ? retrospection emphasizes the root of re- , which is looking back and looking back. On the other hand, introspection emphasizes the root of in- , which is to look inward and observe the depths of your heart.

introspection (English: introspection) or Vipassana) refers to the statement of conscious experience that one can understand through inward examination. Introspection has been discussed by western and oriental philosophers since ancient times, and introspection has always been one of the main methods used by psychologists to study internal psychological activities. Wikipedia

used in computers:

introspection (Introspector) is a default method for the Java language to handle Bean class attributes and events. For example, if the class A has the attribute name , then we can get its value or set a new value through getName , setName . Access the name attribute through getName/setName , which is the default rule.
Java provides a set of getter/setter methods for accessing an attribute in API . Through these API , you don't need to understand this rule (but you'd better figure it out). These API are stored in the package java.beans . The general way of
is to get the BeanInfo information of an object through the class Introspector , and then use BeanInfo to get the property descriptor ( PropertyDescriptor ). Through this property descriptor, you can get the getter/setter methods corresponding to an attribute, and then we can call these methods through the reflection mechanism. Baidu encyclopedia

give an example to see:

import java.beans.BeanInfo;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
...
BeanInfo beanInfo=Introspector.getBeanInfo(UserInfo.class);
PropertyDescriptor[] proDescrtptors=beanInfo.getPropertyDescriptors();
// Bean

from this we can see that the so-called introspection actually means that Java Bean exposes all its internal attributes so that we can obtain or modify their internal attribute values one by one. For a complete example, see here .

GraphQL queries itself to find the functionality it provides, including querying supported fields and submitting support operations.

GraphQL asks GraphQL which types are available by querying the _ _ schema field.

{
  __schema {
    types {
      name
    }
  }
}

this function, which is the introspection of GraphQL, is equivalent to providing rich interface documentation.