1. Post-impressionism
It’s a designation to groups made by painters. Post-impressionism was born after impressionism in the late 1800s till early 1900s.

2. In Finland few painters tried postimpressionism, but only one painter has affected in Finland, Alfred William Finch. He was Belgian-British. He painted inter alia, this.
Postimpressionism took influences from modernism. (Which was before postimpressionism.)
Post-impressionism in art works were more emotional and more simple than impressionism artworks were.

3. Post-impressionism artwork and impressionism artwork.

4. More info about post-impressionism.
In post-impressionism art works are more vivid, colorful and more stylized, as we can see in the pictures before in this lecture. In post-impressionism real-life subjects matters. People have been painted normally, there is not any differences to normal common people. Paintings are pretty modern looking.

5. Sources. Dias 1-4: https://en.wikipedia.org/wiki/Post-Impressionism
and
Pictures:
Picture 1 in 1st dia:
Picture 1 in 2nd dia: French_-_A_Centennial_of_Independence_-_Google_Art_Project.jpg/1024px- Henri_Rousseau_%28French_-_A_Centennial_of_Independence_- _Google_Art_Project.jpg
Picture 2 in 2nd dia: _De_Wellingtonrenbaan_te_Oostende_1888_001.JPG/220px-Willy_Finch_- _De_Wellingtonrenbaan_te_Oostende_1888_001.JPG

6. More sources.
Picture 3 in 3rd dia: _Un_dimanche_apr%C3%A8s- midi_%C3%A0_l%27%C3%8Ele_de_la_Grande_Jatte.jpg/350px- Georges_Seurat_-_Un_dimanche_apr%C3%A8s- midi_%C3%A0_l%27%C3%8Ele_de_la_Grande_Jatte.jpg
Picture 4 in 3rd dia: _Luncheon_on_the_Grass_-_Google_Art_Project.jpg/220px-Edouard_Manet_- _Luncheon_on_the_Grass_-_Google_Art_Project.jpg