Training is teaching, or developing in oneself or others, any skills and knowledge or fitness that relate to specific useful competencies. Training has specific goals of improving one's capability, capacity, productivity and performance. It forms the core of apprenticeships and provides the backbone of content at institutes of technology (also known as technical colleges or polytechnics). In addition to the basic training required for a trade, occupation or profession, training may continue beyond initial competence to maintain, upgrade and update skills throughout working life. People within some professions and occupations may refer to this sort of training as professional development. Training also refers to the development of physical fitness related to a specific competence, such as sport, martial arts, military applications and some other occupations. Training methods of all types can be improved by setting specific, time-based, and difficult goals. This allows for the progressive mastery of a topic with a measured outcome.

Physical training concentrates on mechanistic goals: training programs in this area develop specific motor skills, agility, strength or physical fitness, often with an intention of peaking at a particular time.

In military use, training means gaining the physical ability to perform and survive in combat, and learn the many skills needed in a time of war. These include how to use a variety of weapons, outdoor survival skills, and how to survive being captured by the enemy, among many others. See military education and training.

For psychological or physiological reasons, people who believe it may be beneficial to them can choose to practice relaxation training, or autogenic training, in an attempt to increase their ability to relax or deal with stress. While some studies have indicated relaxation training is useful for some medical conditions, autogenic training has limited results or has been the result of few studies.

Some occupations are inherently hazardous, and require a minimum level of competence before the practitioners can perform the work at an acceptable level of safety to themselves or others in the vicinity. Occupational diving, rescue, firefighting and operation of certain types of machinery and vehicles may require assessment and certification of a minimum acceptable competence before the person is allowed to practice as a licensed instructor.

Some commentators use a similar term for workplace learning to improve performance: "training and development". There are also additional services available online for those who wish to receive training above and beyond what is offered by their employers. Some examples of these services include career counseling, skill assessment, and supportive services. One can generally categorize such training as on-the-job or off-the-job.

The on-the-job training method takes place in a normal working situation, using the actual tools, equipment, documents or materials that trainees will use when fully trained. On-the-job training has a general reputation as most effective for vocational work. It involves employees training at the place of work while they are doing the actual job. Usually, a professional trainer (or sometimes an experienced and skilled employee) serves as the instructor using hands-on practical experience which may be supported by formal classroom presentations. Sometimes training can occur by using web-based technology or video conferencing tools. On-the-job training is applicable on all departments within an organization.

Simulation based training is another method which uses technology to assist in trainee development. This is particularly common in the training of skills requiring a very high degree of practice, and in those which include a significant responsibility for life and property. An advantage is that simulation training allows the trainer to find, study, and remedy skill deficiencies in their trainees in a controlled, virtual environment. This also allows the trainees an opportunity to experience and study events that would otherwise be rare on the job, e.g., in-flight emergencies, system failure, etc., wherein the trainer can run 'scenarios' and study how the trainee reacts, thus assisting in improving his/her skills if the event was to occur in the real world. Examples of skills that commonly include simulator training during stages of development include piloting aircraft, spacecraft, locomotives, and ships, operating air traffic control airspace/sectors, power plant operations training, advanced military/defense system training, and advanced emergency response training like fire training or first-aid training.