Adding content to 101-resolvers

src/roadmaps/graphql/content/105-execution/101-resolvers/100-synchronous.md

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-# Synchronous
+# Synchronous
+
+In GraphQL, a resolver is a function that is responsible for fetching the data for a field in a query or mutation. Resolvers are defined in the schema and are executed by the GraphQL server when a query or mutation is received.
+
+A synchronous resolver is a type of resolver that runs and completes its execution before returning any value. It directly returns the result of the computation, without waiting for any external event such as a database query or a third-party API call.
+
+Learn more from the following links:
+
+- [Get Started with Synchronous](https://graphql.org/learn/asynchronous/)

src/roadmaps/graphql/content/105-execution/101-resolvers/101-asynchronous.md

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-# Asynchronous
+# Asynchronous
+
+In GraphQL, a resolver is a function that is responsible for fetching the data for a field in a query or mutation. Resolvers are defined in the schema and are executed by the GraphQL server when a query or mutation is received.
+
+An asynchronous resolver is a type of resolver that runs, but instead of returning the final value, it returns a promise that will be resolved with the final value. This allows the resolver to wait for an external event such as a database query or a third-party API call to complete before returning the result.
+
+Learn more from the following links:
+
+- [Get Started with Asynchronous](https://graphql.org/learn/execution/#asynchronous-resolvers)

src/roadmaps/graphql/content/105-execution/101-resolvers/102-scalar-coercion.md

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-# Scalar coercion
+# Scalar Coercion
+
+In GraphQL, scalar coercion is the process of converting a value from one type to another, as it flows through the resolvers. This is needed when the input value for a field does not match the expected type, but can still be successfully converted to the correct type.
+
+Scalar coercion can be implemented in the resolvers by using the **GraphQLScalarType** constructor to define a custom scalar type and providing a **coerce** function that can convert the input value to the correct type.
+
+Learn more from the following links:
+
+- [Get started with Scalar coercion](https://graphql.org/learn/execution/#scalar-coercion)

src/roadmaps/graphql/content/105-execution/101-resolvers/103-lists.md

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-# Lists
+# Lists
+
+In GraphQL, a list is a type that represents an ordered collection of items. Lists can be used as the return type for a field in a query or mutation, and can contain any type of items, including scalars and objects.
+
+The resolver function for a list field can retrieve the data from a database or a third-party API and return it as an array. 
+
+Learn more from the following links:
+
+- [Get started with Lists and Non-Null](https://graphql.org/learn/schema/#lists-and-non-null)

src/roadmaps/graphql/content/105-execution/101-resolvers/index.md

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-# Resolvers
+# Resolvers
+
+In GraphQL, a resolver is a function that is responsible for fetching the data for a field in a query or mutation. Resolvers are defined in the schema and are executed by the GraphQL server when a query or mutation is received.
+
+Each field in a GraphQL schema has a corresponding resolver function that is responsible for returning the data for that field. The resolver function can retrieve the data from a database, a third-party API, or any other source, and return it to the client.
+
+Learn more from the following links:
+
+- [Complete guide to Resolver](https://www.apollographql.com/docs/apollo-server/data/resolvers/)
+- [Tutorial - Resolvers](https://www.tutorialspoint.com/graphql/graphql_resolver.htm)