It depends as there is no right or wrong answer. But the trend these days is to install the flooring first and before the kitchen cabinets are installed. Installed the flooring first may have its advantages during a kitchen renovation project.

Before you can get to the answer to this question, you should look to clarify the following queries because the answer will depend upon what your preferences are. 

Are you looking to save money?

If you choose not to install the flooring first, you would install the cabinets first, which will mean less material or less wooden tiles required and would save a small percentage of cost. It is important to notice however that the expected savings during this kitchen renovation would not be huge because the area under the cabinets is not significant enough to add substantial cost. Wooden flooring, which is the most common material to be used in single family kitchens, is not typically very expensive.

Is the floor level the same everywhere and what is the location?

Sometimes the kitchen needs to be installed in the basement where the floor level is not the same. You may not want to install your cabinets on an uneven floor. Installing the flooring first may give you a chance to level the floor first using the materials underneath the floor. 

Do you intend to make design changes to the kitchen later on?

If there may be a need to redesign the kitchen at a later date, then you should certainly look at installing the flooring first because you would want to cover the entire floor evenly and not leave gaps in the flooring. It could be a problem if you move your cabinets and you are left with areas with no floor underneath. The same flooring may not be available in stores when you need it and you may find it impossible to find the same flooring to cover the gaps left by cabinet removal. 

In most of the recent renovations I have witnessed, the trend is to install the flooring first. This also makes it easier to install the flooring because you can install it right upto the wall, which is straight forward and much easier rather than installing upto the cabinets, which would require staggering the flooring. In addition, this also gives you a lot of flexibility for changing the kitchen design. The only difference between flooring under the cabinets compared to flooring elsewhere would be that you would not need baseboards where the cabinets are to be installed.