Largely as a consequence of Covid-19, Cambridge English Assessment, the body that is responsible for standards and regulations for the CELTA course, and which issues the CELTA certificate, decided to allow courses to be run fully online for the first time.
Of course, what many people don't know, is that the "Online CELTA" had been in existence for a number of years already. Cambridge had teamed up with International House to put together a Moodle platform with content (texts, videos, activities and exercises, forums and audio texts) that matched the content of the CELTA syllabus--in other words, the input that had until then been delivered exclusively by trainers on face-to-face CELTA courses.
Input and Teaching Practice
The contact hours on these courses could effectively be divided into input and teaching practice. The former are trainer-led sessions that address the vital basics of teaching English as a foreign language, i.e., the CELTA syllabus. Teaching practice included actual teaching of students (observed by both trainers and fellow candidates), oral feedback on that teaching practice, and assisted lesson planning (in which all candidates participate communally).
On the original online CELTA course, face-to-face input was replaced by online (Moodle) input, allowing for more flexibility in delivery. When I set up the British Council Singapore's online course, we had candidates go through input almost entirely before starting teaching practice. This allowed, for example, candidates based in Malaysia or Hong Kong to come to Singapore only for the teaching practice portion of the course, which cut down their stay there to two and a half weeks, rather than the four they would have to stay had they had both components of the course--input and teaching practice--been face-to-face.
The Pivot: Online Teaching Practice