The really long version of differences and probably more information than you originally wanted.

These switches were originally made by "Cherry Switch" but is now part of "ZF Switches".
Original series = "DA" -- no longer made, Replaced with "DB" series.
Regarding DB series - there are a bunch of choices within the series regarding contact types, terminals, actuators, etc.

The switches have ratings and life spans based on UL and EU ratings.
In the US - we use UL ratings for nearly everything and they tend to be on the pessimistic side (Canadian CSA tends to be very similar to UL). The EU rating system tends to be more lenient than the UL rating. The EU ratings have higher current loading and cycle counts and tend to be more on the optimistic side.

Two most important ratings of these switches are cycles and loading.

These switches have two basic 'cycle' ratings: Operation cycles (number of cycles while switch is under power load so is definitely contact dependent) and Mechanical cycles (number of cycles while switch has no power load and is affected by contact mass). UL ranges of operation cycles varies from 6,000 cycles to 100,000 cycles. UL ranges for mechanical cycles is 15,000,000 cycles for all but DB2 and DB7 which are rated at 10,000,000 cycles (higher contact mass).

Loading depends on contact types. There are seven contact versions within DB series. Going by the UL ratings:
DB1 = environment temperature range up to 120C, Contact current rating up to 5 amps up to 250VAC or 1A up to 48VDC. Rated number of operation cycles = 6000. Silver plated nickel contacts. Button operating force = 150cN engage, 60cN release. Somewhat replaced the old "DAB" switches.

DB2 = environment temperature range up to 120C, Contact current rating up to 10 amps up to 250VAC and not rated for DC operation. Rated number of operation cycles = 6000. Silver plated nickel contacts. Button operating force = 250cN engage, 100cN release.

DB3 = environment temperature range up to 120C, Contact current rating up to 0.1 amps up to 250VAC or 0.1A up to 30VDC. Rated number of operations cycle = 100,000. Has gold plated platinum contacts and not intended for high current interruption, more intended for use within switch matrix or similar use. Button operating force = 150cN engage, 60cN release. Directly replaced the old "DA3" switches.

DB4 = no longer defined on mfr website defined but appears to be a 4 amp (AC) and 1 amp (DC) version.

DB5 = environment temperature range up to 85C, Contact current rating up to 1 amp up to 250VAC or 1A up to 48VDC. Rated number of operations cycle = 6000. Silver plated nickel contacts. Button operating force = 150cN engage, 60cN release. Essentially a Lower current and temperature version of DB1. Somewhat replaced the old "DAB" switches. Not really intended for use within a switch matrix but will work. More for switching light loads such as a small solenoid or motor.

DB6 = environment temperature range up to 85C, Contact current rating up to 5 amps up to 250VAC and not rated for DC operation. Rated number of operations cycle = 6000. Silver plated nickel contacts. Button operating force = 250cN engage, 100cN release. Lower current and temperature version of DB2. Somewhat replaced the old "DAB" switches.

DB7 = environment temperature range up to 85C, Contact current rating up to 10 amps up to 250VAC and not rated for DC operation. Rated number of operations cycle = 6000. Contact type not specified on ZF webpage. Button operating force not specified on ZF webpage.

Most popular style for pinball machine use is DB3:
Part numbering example --
DB3 (DA3 replacement) is the low current, low resistance, long life version of the microswitch. Tends to be the most commonly offered version as part number DB3C-B1AA (standard popular version from the manufacturer). This includes no actuator and you need to reuse your existing actuator. This switch is intended for low current use only such as within a switch matrix.
DB3C-B1AA:
DB3 = Series
C = SPDT type switch, A = SPST Normally Open, B = SPST Normally Closed. Type C replaces both types A and B.
B1 = 0.110 type quick connect type terminals (standard terminals for solder on or quick connects)
AA = standard spherical head with no added actuator.

None of these are rated high enough in current rating for direct drive of a DC solenoid. DB1/DB5 is the closest but only up to 1 amp. The DB3 version is best choice for operating within a switch matrix type circuit.

A note about button operating force.
Original switch buttons on the old switches such as DA3 had an operating force of 90 grams or about 89cN so it takes more force to operate the new series of switches. The forces listed are "Button" forces. Once you add an actuator (lever, roller, etc) - the operating force goes down. The amount of force then becomes a function of the actuator length and type.

To add to this -- the three versions mentioned by Lloyd:
Easy push ( used in pinball for years ) = Switches less than ~100 grams (such as DA3 at 90 grams).
Medium push ( works in pinball ) = Switches between ~100 and ~150 grams (such as DB3 at 150cN or about 150 grams).
Sometimes the actuators need to be messed with to get this switch to work.
There is a 150 to 200 gram range that is hit and miss as to where they work.
Hard push = Switches in the ~200 gram range and up.

For comparison - a standard pinball ball weighs in at 2-7/8 ounces or about 81.5 grams.
And remember that the above force is rated at the button and not at the actuator. The force required is reduced by the length of the actuator but this also increases the throw length (we all remember Statics class, right?).