Is Faster RCNN the same thing as VGG-16, RESNET-50, etc... or not?
Image Classification Models are commonly referred as a combination of feature extraction and classification sub-modules. Where the total model excluding last layer is called feature extractor, and the last layer is called classifier.
Popular Image Classification Models are: Resnet, Xception, VGG, Inception, Densenet and Mobilenet.

Object Detection Models are more combination of different sub-models rather than single end to end connected models, as you mentioned it is more like an architecture. Object detection model contains a feature extraction model, region proposal network, classification and regression models. Here the above mentioned classification models (Resnet50, VGG, etc) excluding all dense layers are used as a feature extractors.
Some of the popular object detection models are: Region-based Convolutional Neural Networks(R-CNN), Spatial Pyramid Pooling(SPP-net), Fast R-CNN, Faster R-CNN, Regression-based object detectors, YOLO(You only Look Once),Single Shot Detector(SSD).