Files naming convention for external methods

I am wondering what is the difference between utils vs helpers vs resolvers vs services as a directory name for external methods. For example I want to create a special object that function as a list but can only pushed and not popped:

const specialObjectArray = () => {
    const objects = [];

    const object = {
        push: (data) => routes.push(data),
    };

    return object;
};

Which one it fits the most? What is the difference between the 4 names I listed above? Best Practice for those?