Science

How Neural Networks Work: Principles and Technology Impact

8 min read · 21 September 2026
Illustration for the article “How Neural Networks Work: Principles and Technology Impact”

Neural networks operate by mimicking the human brain through multilayered structures of artificial neurons that learn from vast datasets to recognize patterns, make decisions, and generate information. They build complex relationships between input data and outcomes, enabling tasks previously achievable only by humans.

Understanding how neural networks work is crucial to assessing their impact on modern technology — from voice assistants and recommendation systems to manufacturing automation and healthcare. In this article, we examine exactly how neural networks form the foundation of innovation and transform familiar processes, opening new opportunities for digital world development.

Comparison of popular neural network models by parameters
Model Number of layers Training time Application area
GPT-4 96 Several months Text processing, generation
ResNet-50 50 2–3 weeks Computer vision
Yolo v8 107 1 month Object recognition
BERT 24 3 weeks Natural language processing
  • 96 layers number of layers in the GPT-4 model
  • $12 million training cost of the GPT-4 model
  • 2 MW data center power consumption for a large neural network
  • 95% accuracy of neural networks in cancer diagnosis
  • 60% share of applications with generative AI in 2026

What is an artificial neural network and what components does it consist of?

An artificial neural network is a computational model made up of interconnected neurons organized in layers, capable of learning and solving complex data processing tasks by imitating the principles of biological brain function.

Neural network structure

A neural network includes three main types of layers: input, hidden, and output. Each layer contains many neurons that process information. A typical deep neural network has from 5 to 50 layers, but modern models such as GPT-4 reach 96 layers, greatly expanding their capabilities in text analysis and generation.

  • Input layer — receives the initial data.
  • Hidden layers — perform complex transformations, uncovering patterns.
  • Output layer — produces the final result.

How a neuron works

A neuron performs a weighted sum of input signals, then applies an activation function, such as ReLU, to introduce nonlinearity. Neural network training uses the backpropagation algorithm, first formalized in 1986, which adjusts weights to minimize the difference between predicted and actual results.

How are modern neural networks trained and what does it cost?

Training process

Training modern neural networks requires significant computational resources and enormous datasets. For example, GPT-4 was trained on texts totaling over 570 billion tokens, giving the model a deep understanding of language. Training this model took several months on Microsoft Azure supercomputers using about 10,000 graphics processing units (GPUs). For computer vision tasks, the popular ResNet-50 architecture is typically trained for 2–3 weeks on 8 GPUs, which is significantly less time and resources compared to large language models.

Costs and resources

Training models at the GPT-4 level costs tens of millions of dollars, with an estimated price around $12 million, factoring in supercomputer runtime and energy consumption. Meanwhile, computer vision models like ResNet-50 require smaller investments: renting 8 GPUs at roughly $50 per hour can complete training within a few weeks. Thus, the cost and scale of training neural networks heavily depend on the chosen architecture and dataset size.

  • GPT-4: trained on 10,000 GPUs, several months, cost about $12 million
  • ResNet-50: 2–3 weeks on 8 GPUs, price around $50 per hour
  • Data volume for GPT-4 — over 570 billion tokens

What technologies in everyday devices use neural networks?

Neural networks in everyday devices are used to enhance image processing, speech recognition, and autopilot control, improving user experience quality and safety.

Mobile devices

In Apple iPhone 15 Pro smartphones, neural networks operate in Smart HDR 5 mode, automatically enhancing photo quality by analyzing scenes and dynamic range. The cameras process up to 1 billion operations per second, enabling clearer and more balanced shots in low light. The iPhone 15 Pro starts at 120,000 rubles, reflecting the device’s high-tech capabilities. Similarly, Google Translate apps use neural network models for instant text and speech translation, supporting over 100 languages in real time.

Smart home and transportation

Yandex.Station Max smart speakers are equipped with neural networks for voice recognition accuracy above 95%, allowing effective interaction even in noisy environments. In transportation, the Tesla Model 3 uses the Autopilot system based on neural network algorithms that process data from cameras and sensors for autonomous driving. This system can reduce accident risks and supports autopilot functions at speeds up to 150 km/h, making it one of the most advanced mass-produced solutions.

  • Apple iPhone 15 Pro: processes up to 1 billion operations per second in Smart HDR 5
  • Yandex.Station Max: voice recognition accuracy over 95%
  • Tesla Model 3 Autopilot: supports autonomous driving up to 150 km/h
  • Google Translate: instant translation of over 100 languages

What limitations and errors do neural networks have in 2026?

In 2026, neural networks face significant limitations, including high energy consumption, susceptibility to overfitting, vulnerability to specialized attacks, as well as unresolved privacy and ethical issues related to handling personal data.

Technical limitations

Modern large neural network models require enormous computational resources: data center energy consumption for training such systems reaches 2 MW, equivalent to the daily usage of several hundred homes. For example, OpenAI’s GPT-4 model is known for overfitting tendencies, sometimes producing inaccurate or outdated facts, which reduces the quality of generalization. This limitation stems from balancing training data volume and model architecture.

Security and ethics

Neural networks remain vulnerable to adversarial attacks—specialized input manipulations that can reduce image and audio recognition accuracy by up to 10%. This risk level is especially critical for applications in medicine and security. Additionally, legal regulations regarding personal data protection and ethical standards for information processing in 2026 remain partially unresolved, posing challenges for companies using AI in commercial and government systems.

  • Data center energy consumption: up to 2 MW for a large model
  • Recognition accuracy drop due to adversarial attacks: up to 10%
  • GPT-4 model: example of overfitting and inaccurate generalization

How are neural networks shaping the future of technology and what trends dominate in 2026?

Generative AI

In 2026, generative neural networks are the key driver of technological progress, with over 60% of new AI applications including a generative component, greatly enhancing content creation and task automation capabilities. For instance, OpenAI’s GPT-5 model is already used in business environments for text and code generation, while DALL·E 3 is actively employed to create visual images for marketing and design.

One of the most important trends remains the development of multitask models capable of processing text, images, and sound simultaneously, enabling integrated solutions for communication, education, and entertainment. Such versatility opens new horizons for AI applications across industries.

Energy efficiency and application areas

The push for energy efficiency has become critically important: modern models using quantization and sparsity reduce resource consumption by up to 40%, lowering computing costs and environmental impact. For example, the NVIDIA A100 with quantization optimization demonstrates high performance while cutting energy use.

In healthcare, neural networks have achieved about 95% accuracy in cancer diagnosis from medical images, already being implemented in clinics to improve diagnostic speed and quality. Major medical institutions use these technologies for early disease detection and personalized treatment.

  • Over 60% of new AI applications in 2026 include generative models
  • Costs cut by 40% thanks to quantization and sparsity
  • AI accuracy in cancer diagnosis reaches 95%

Frequently Asked Questions

What distinguishes deep neural networks from simple ones?
Deep neural networks have more than 5 layers, enabling them to detect complex dependencies; for example, GPT-4 contains 96 layers.
How much does training a large neural network cost today?
Training GPT-4-level models costs about 12 million dollars and takes several months on thousands of GPUs.
Where do I encounter neural networks in everyday life?
Neural networks are used in Apple iPhone 15 Pro smartphones, Yandex.Station Max smart speakers, and Tesla Model 3 autopilot.
What are the main limitations of neural networks in 2026?
Limitations include high energy consumption (up to 2 MW for large models) and vulnerability to specialized input attacks.

Key Takeaways

  • Neural networks consist of layers of neurons trained using backpropagation
  • Training large models costs millions of dollars and requires thousands of GPUs
  • Neural networks are already integrated into mobile devices, smart homes, and cars
  • High energy consumption and vulnerabilities remain major challenges
  • The future lies with generative AI and energy-efficient models