Low-rank adaptation (LoRA) is a parameter-efficient fine-tuning technique for customizing large language models. It trains low-rank update matrices while keeping most pretrained parameters fixed, reducing the barrier to model customization. section 11.4
LoRA belongs to a broader shift toward accessible open-model development, alongside QLoRA and lightweight alignment methods. Its efficiency can widen participation, while customization still requires infrastructure and responsible model governance. section 11.4
Table 11.2 Comparing open and closed LLMs
| Trade-offs |
Open source LLMs |
Closed source LLMs |
| Transparency |
Full access to weights, architecture, and sometimes data |
Opaque methods, weights, and training data |
| Accessibility |
Downloadable, runnable offline, and modifiable |
API access controlled by the provider |
| Safety alignment |
Varies widely; depends on developer practices and community norms |
Extensive internal testing and standardized safeguards |
| License clarity |
Apache, MIT, RAIL, custom terms; sometimes vague or restrictive |
Proprietary terms of service |
| Customization |
Fully customizable via fine-tuning and architectural changes |
Limited to API parameters or provider tooling |
| Infrastructure burden |
Requires local compute, setup, and deployment |
Hosted by the provider |
| Risk of misuse |
Higher; fewer enforced safeguards, and fewer default protections |
Moderated through platform enforcement and terms of service |
Compare customization access, infrastructure demands, transparency, and misuse risks for open and closed language models. section 11.4








