Techniques

Deep Learning

Deep learning is a subset of machine learning that uses artificial neural networks with many layers (hence "deep") to learn representations of data. By stacking layers of neurons, deep networks can automatically extract hierarchical features — from pixels to edges to shapes to objects — without hand-crafted feature engineering.

How Deep Learning Works

A deep neural network consists of an input layer, multiple hidden layers, and an output layer. During training, data flows forward through the network (forward pass), predictions are compared to ground truth via a loss function, and gradients are propagated backwards (backpropagation) to adjust weights using optimisers like Adam or SGD. Modern deep learning is powered by GPUs, large datasets, and architectural innovations like convolutional networks (CNNs), recurrent networks (RNNs), and transformers.

Key Use Cases

  • Image and video recognition
  • Natural language processing and translation
  • Speech recognition and synthesis
  • Drug discovery and protein structure prediction
  • Autonomous vehicle perception
  • Recommendation systems
  • Fraud detection

Frequently Asked Questions

What is the difference between deep learning and machine learning?
Machine learning covers all algorithms that learn from data, including decision trees, SVMs, and neural networks. Deep learning is a specific subset of ML using neural networks with many layers, capable of learning complex hierarchical patterns from raw data without manual feature engineering.
How much data does deep learning need?
Traditional deep learning is data-hungry, typically requiring thousands to millions of labelled examples. However, transfer learning, few-shot learning, and foundation models have dramatically reduced data requirements for specific tasks.
What hardware is needed for deep learning?
Deep learning training typically uses GPUs (NVIDIA) or TPUs (Google) for their parallel processing capabilities. Inference can run on CPUs, mobile chips, or specialised AI accelerators depending on latency and cost requirements.
What companies lead in deep learning?
Key deep learning infrastructure companies include NVIDIA (hardware), Google DeepMind, OpenAI, Meta AI Research, and Hugging Face. Applied companies using deep learning span healthcare, autonomous vehicles, NLP, and computer vision.