What are the six jumps and how do combinations and sequences differ?

Skate Canada lists the jumps in order of difficulty: Toe Loop, Salchow, Loop, Flip, Lutz, Axel. Each is valued in the Scale of Values by its number of revolutions.

• Toe Loop: toe jump, natural rotation, taken off from a backward outside edge.
• Salchow: edge jump, natural rotation, taken off from a backward inside edge.
• Loop: edge jump, natural rotation, taken off from a backward outside edge.
• Flip: toe jump, natural rotation, taken off from a backward inside edge.
• Lutz: toe jump with counter rotation, taken off from a backward outside edge.
• Axel: edge jump, natural rotation, taken off from a forward outside edge. A single Axel has one and a half rotations, unlike other single jumps, which have one.

Jump elements are an individual jump, a jump combination or a jump sequence:

• Jump combination: two or more jumps where the landing foot of the first jump is the take-off foot of the next, with no change of foot or turn between them. One full revolution on the ice between the jumps keeps it a combination.
• Jump sequence: two or three jumps of any number of revolutions in which the second and/or third is an Axel-type jump, with a direct step from the landing curve of the previous jump to the take-off curve of the Axel jump.

Source: Skate Canada, Scoring of Skate Canada Competitions (glossary), https://info.skatecanada.ca/index.php/en-ca/rules-of-sport/52-marking-of-skate-canada-competitions.html