Tech Point

A Tech Point (TP) is technically the "cost" of each part to put on your build. Each chassis has a set number of TP and can be equipped only with parts with a total sum or less of that number of TP. e.g. a chassis with 8 TP can only be equipped with parts whose TP add up to 8 or less.
There are a set number of parts excluding chassis that add TP to your build instead of cost TP. The TP for those parts will appear with a green background and will have the ability "Tech UP: This part adds Tech Points".
Generally, a part with more TP will be better than one with less by having more stats and/or better abilities. Note that having more TP doesn't always make a part better. Rarity is also a factor you should consider and the fact that not all parts are suitable for all builds.