It means your total wattage is restricted to about 7000 watts draw. That used to be a lot, back in the day, but with an AC unit, computers, refrigerator, and other assorted lighting and fans, phone chargers, microwave oven, washer/dryer and etc., 60 amps is used up pretty quick. Some water heaters, AC units, and electric stoves/ovens can take a 60 amp circuit all to themselves.
Some electric companies won't provide 60 amps for new service anymore because it is too little for most modern homes in America. Actually having a microwave oven and a window air conditioner and a refrigerator going at the same time will take 60 amps through three 20 amp circuits (that's a maximum, they are usually pulling between 10 and 15 amps each).