TechData contains multiple important parameters concerning technologies stats and values. Lets use basic tech as an example:

"basic": {
  "techUnlocks": [
    "organization",
    "climbing",
    "fishing",
    "hunting",
    "riding"
  ],
  "unitUnlocks": [
    "giant",
    "bunny",
    "scout",
    "transportship",
    "warrior",
    "babydragon",
    "firedragon",
    "dagger"
  ],
  "improvementUnlocks": [
    "city",
    "ruin",
    "landfill"
  ],
  "movementUnlocks": {
    "field": 1,
    "forest": 2,
    "ice": 1,
    "wetland":2
  },
  "cost": 0,
  "idx": 0
},

Specifies enum value of the tech, used as a key:

"basic": {

Here is all vanilla types currently in the game:

Basic,
Riding,
FreeSpirit,
Chivalry,
Roads,
Trade,
Organization,
Shields,
Farming,
Construction,
Fishing,
Whaling,
Aquatism,
Sailing,
Navigation,
Hunting,
Forestry,
Mathematics,
Archery,
Spiritualism,
Climbing,
Meditation,
Philosophy,
Mining,
Smithery,
FreeDiving,
Spearing,
Riding2,
ForestMagic,
WaterMagic,
Frostwork,
PolarWarfare,
Polarism,
Oceanology,
Shock,
Recycling,
Hydrology,
Diplomacy,
Aquaculture,
FishingSimple,
Sledding,
IceFishing,
Pescetism,
Ramming,
AquaBase,
MarineLife,
AquaFishing,
Waterways

Specifies int enum value of the tech.

"idx": 0

Specifies cost tier of the tech.

"cost": 0,

Specifies other techs which are can be bought after bying this tech.

"techUnlocks": [
  "organization",
  "climbing",
  "fishing",
  "hunting",
  "riding"
],

Specifies improvements unlocked after bying this tech.

"improvementUnlocks": [
  "city",
  "ruin",
  "landfill"
],

Specifies units unlocked after bying this tech.

"unitUnlocks": [
  "giant",
  "bunny",
  "scout",
  "transportship",
  "warrior",
  "babydragon",
  "firedragon",
  "dagger"
],

Specifies player abilities unlocked after bying this tech. As basic tech has no player abilities unlocked by it, lets take example from free spirit tech:

"abilityUnlocks": [
  "disband"
],

Here is all vanilla player abilities currently in the game:

Disband
Destroy
Literacy
Glide
Decompose
PeaceTreaty
Embassy
CapitalVision
Dividend
Discipline
Pontoon
Treehouse
Bubble

Specifies tasks unlocked after bying this tech. As basic tech has no task unlocked by it, lets take example from trade tech:

"taskUnlocks": [
  "wealth"
],

Specifies terrain movement unlocked after bying this tech.

"movementUnlocks": {
  "field": 1,
  "forest": 2,
  "ice": 1,
  "wetland":2
},

Specifies terrain defence bonuses unlocked after bying this tech. As basic tech has no defence bonuses unlocked by it, lets take example from aquatism tech:

"defenceBonusUnlocks": {
  "water": 15,
  "ocean": 15
},