When one talks about offering or chöpa, there are many kinds of offering. There are external or chiyi chöpa (ཕྱི་ཡི་མཆོད་པ་), internal or nanggi chöpa (ནང་གི་མཆོད་པ་), secret or sangwai chöpa (གསང་བའི་མཆོད་པ་) and ultimate offering de khonanyid kyi chöpa (དེ་ཁོ་ན་ཉིད་ཀྱི་མཆོད་པ་).
External offering refers to things like offering pleasant sense-fields such as pleasant visual objects, sound, taste, smell, etc. This is called the offering of five sense objects or doyön nga. It can also include offerings of good things that are owned by oneself or dakpö yongsu zungwa (བདག་པོས་ཡོངས་སུ་བཟུང་བ་) such as one’s wealth and offering of good things that are not owned by oneself or dakpö yongsu mazungwa (བདག་པོས་ཡོངས་སུ་མ་བཟུང་བ་) such as a wildflower. One can also offer one’s body, abode and possessions nélülongchö (གནས་ལུས་ལོངས་སྤྱོད་). One of the most common forms of offering is to offer the entire world with all the good things in it.
Similarly, one can offer real things such as water, tea, clothes, etc. which one has or ngösu jorwa (དངོས་སུ་འབྱོར་བ་) and also imaginary things or yikitrülpa (ཡིད་ཀྱི་སྤྲུལ་པ་). The best form of imaginary offering is to follow the example of the offering made by Bodhisattva Samantabhadra. One must imagine all good things and then multiply and magnify them to fill the entire space and offer them to the Buddhas. This is called the cloud of offering of Samantabhadra or Küntuzangpö Chötrin (ཀུན་ཏུ་བཟང་པོའི་མཆོད་སྤྲིན་).
In addition to external offerings, one can offer good things within oneself. One can offer one’s body, the experience of happiness and joy, one’s virtues and merits accumulated so far, one’s good qualities and achievements, and the enlightened qualities latent in one’s mind. This will be internal offering.
Then, there is the concept of secret offering in tantric Buddhism. For example, a devotee can offer the five kinds of nectars and five kinds of meats, which are substances generally considered very filthy and impure. They are consumed to overcome one’s habitual prejudices and conventional taboos. They are considered nectar because, when used in the right way, they destroy the ordinary sense of duality and defilements. There is also the offering of great bliss generated through the use of the psycho-somatic energies, energy channels and vital air. These are secret offerings.
Finally, there is the ultimate offering in which all sense of duality is dissolved. There is no offering, no one making the offering and no one receiving the offering. Abiding in such awareness of the basic nature of one’s mind is the ultimate form of offering.