Can anyone give me the meaning of YIMBY.. i am quite lost and by the way what are stage 7, stage 8 buildings... Please give me examples of buildings of all stages...

YIMBY means "yes in my backyard", referring to things that boost desirability. For example, a plaza is a YIMBY for commercial areas and parks are a YIMBY for residential areas.

Stage limits are population milestones that you must reach before moving towards taller and taller buildings. For residential and commercial buildings: stages 1-3 are low density, 4-6 are medium density, and 7-8 are high density. For example, you must reach stage 3 (low density) before attempting to zone medium density (stage 4.)

To put it in simpler terms...
You should not zone any residential medium-density until your regional population reaches about 1,000. You should not zone any residential high-density until your regional population reaches 26,000. NOTE: Even if you reach these populations, the chance of getting a larger building is still low. You would probably need at least 100,000 residents in your region to start getting high-rises more frequently. The good news is that the higher your population, the more high-rises you can get.

As for commercial office, that ONLY reflects your commercial office population. Offices have the same stage limits as residents, but remember, you must have 26,000 commercial office jobs to see high-density offices, NOT 26,000 residents. They are completely separate. Services don't behave anything like residential/office limits as they do not take as long to get their largest.

Here are some examples.
Residential (stages 1-3): Cute House, Bungalows, 2 Story House, Victorian Mansion....basically just detached homes.
Residential (stages 4-6): Brick Walk-up, 3 Story Row House, Small Condos, Wilsonoff Condos, Ngo Manor.
Residential (stages 7-8): Large Tenement, Reed Place, Wallace Manor, Ong Condos, McCarthy Condos

Offices (1-3): Lam Banking, Byall Means Travel Agency, McCord Printing, Chalmers Co.
Offices (4-6): Grove Consulting, Brink Real Estate, Leong Accountants, Bunch Engineering, Fennel Corporation
Offices (7-8): Vu Financial, Hourvitz Accounting, van Prooijen Trading, Yates Real Estate, Hurt Enterprises

i see....is Farly Audio a stage 6 building ? Do all stage 8 buildings have to occupy 4x4 zoning?

no, there are some stage 8 buildings that take up 2 x 2 only. most are 3 x 3 or larger though.

True, but I think most stage 8's will come from 4x4 lots. Farly Audio is something like a stage 5 or 6. Anyways, the point is you can get a Farly Audio by zoning medium-density commercial. You don't have to zone high-density to get the medium staged buildings. You can get stages 1-3 on low density, stages 1-6 on medium density, and stages 1-8 on high density. It's most logical to just evolve the city's size instead of zoning high-density upfront, but that's up to your preference of course.

What about Bell Tower and Ryan Apartments... i mean what stages are they

Those two towers are among the tallest residential towers there! They're stage 7, I think, because there are some Residential towers that hold up to five times as many Sims which would qualify as stage 8s.

These 4 buildings just popped out like that...Long apartments, Bell towers, Ryan Apartments and Simon Manor just came out suddenly. But, they only appear at a certain corner. These buildings cannot be found anywhere in my city accept right at the corner and I am quite suprised... I did not zone any 4x4..and my population is only 45k when they appeared. ???

it looks like you broke the stage 8 barrier in that area of your city congradulations.

But they only appear in that certain area and they appear in a group....In the other areas, i only have small apartments or tenements but in another area there is a grossman apartments. Can anyone tell me why they only appear in that area??

maybe the area has a high deserverbly for a certain group, watter? parks? plazas? conjestion? pollution?

My city reached a population of over 2 million recently, but i don't have the the great buildings like posted here i guess my biggest residential is Ryan Appartments or the Bell Towers. Can i get even higher towers or do I have to buy Rush hour for skyscrapers like those in san fransisco, riverside etc.

Wait!!1 My bell towers suddenly was abandoned and it turned into a low wealth building housing 6418 people(the lowest wealth and I turned off the game) the stats of the building are low polution, low crime, medium commute, medium traffic noise, school grade and hospital grade are high...why is the building abandoned

medium commute, medium traffic noise!

high wealth are very sensitive.

How do you reduce traffic noise Syd-hk and the commute... i thought it was good enough... i am trying to save that tower because it is the only one there