Essentially, a jigsaw is used for cutting curves and stenciled designs. Some other tools will emulate many of the functions of a jigsaw so it may not always be needed for some projects. There are many other electric saws on the market and choosing the correct one can make completing a task much easier.
Hand saws, such as coping saws, have a very thin blade but operate excellently when cutting shapes out of wood. The blade is almost as thin as wire but they have the flexibility to cope with intricate projects such as lettering, stenciling or fret work. This is ideal if the structure of your project involves curved lines.
A Fret saw works very similar to a coping saw. This saw is used mainly in the creation of fretwork but it can also be used as a non-electrical alternative to a jigsaw. The very fine blade works its way around the smallest of curves and corners to produce excellent results.
The difference between the reciprocating saw and a jigsaw comes down to operation. The jigsaw is a horizontally held saw which is held in line with the flat surface while the reciprocating saw is used perpendicular to the flat surface. Cutting stencils and curves is possible with a reciprocating saw.
For bigger projects, it might be advisable to use a band saw. This has a vertical blade. A disadvantage to using a band saw is that the blade can only move up and down from two fixed points and the wood has to be moved around the blade. Jigsaws are portable enough to move around the wood.
A rotary saw is great for cutting a shape into a piece of wood. While you would have to drill a pilot hole and then use your jigsaw to cut the curves in a piece of material, the rotary saw is able to complete this project using just the one tool. Rotary saws cut their own pilot holes by using a spiral blade. This allows the tool to cut downwards as well as horizontally.
A hack saws will only suit a project if you intend you cut in a straight line. A hack saw is limited to cutting at right angles and is not ideal for curves. A jigsaw would usually be a better option on work of an ornate nature.
For bigger projects it might be advisable to use a scroll saw which has a vertical blade. One disadvantage with using a band saw in relation to certain projects is that the blade is in a fixed state. This limits the amount of versatility it has when compared to a jigsaw.
Jigsaws are used mainly for woodworking but they can cut metal too. They are particularly useful for cutting irregular shapes from wood such as curves and stencils. There are a variety of different blades that can be used on a jigsaw which can all cope with different types of materials. Replacement blades are easy to source and are relatively inexpensive.